Research Projects : Export

Main objective

To better characterize cholera transmission in cholera hotspot in DRC and assess the impact of a large vaccination campaign reaching high coverage on sustained control of cholera transmission for at least two years.

Methods

Clinical surveillance (Goma and Bukama)
Observational surveillance study at CTC/CTU level, including all patients in all active structures of the zones (ZS Goma, Karisimbi, Nyiragong, Kirotshe and ZS Bukama). Systematic RDT testing, questionnaire, collection of dry and humid filter papers

Seroprevalence surveys (Goma and Bukama) – collecting venous blood samples
Goma: 6 serosurveys at different time of the year (all post-vaccination). Bukama: 3 serosurveys once a year (1 before vacci, then 1 and 2 years after), + mortality survey

Home follow-up (Goma only)
Repeated home visits for RDT positive cases (D1, D4, D7, D14, D28, D90 and D180). Stool testing from the family, questionnaire, collecting environmental samples.

Evaluate the impact of OCV preventive campaigns at different levels:

• Impact on number of cholera cases: symptomatic cases in CTC/CTUs
• Impact on transmission in the community: monitoring level of immunity in the population including asymptomatic cases
• Impact on transmission at household level

This study will help us better understand the impact of mass cholera vaccination programs to set expectations for decision makers and help understand when revaccination may be needed.

Cholera remains a public health concern in Ethiopia. We aim to contribute to reducing the burden of cholera and generate scientifically strong data on the effectiveness and impact of OCV (Euvichol-Plus) vaccination in target areas in Ethiopia, as well as various aspects of cholera epidemiology. This includes the disease burden, disease severity and fatality, transmission and carriage/shedding, site-specific risk factors and healthcare seeking behaviour associated with cholera, etiologies of non-cholera diarrheal diseases and antimicrobial resistance, and etc. This project will contribute to the country’s efforts towards the national cholera plan (NCP), with evidence-based data to be generated and stakeholder engagements in alignment with the WHO Global Task Force for Cholera Control (GTFCC) ‘Ending Cholera – Global Roadmap to 2030’.

Objective

Evaluate the effectiveness of the Case Area Targeted Intervention (CATI) approach in reducing the incidence of new cases during cholera outbreaks.  And in so doing, to determine factors that support optimal delivery and interventions for CATIs towards cholera reduction in humanitarian settings and fragile states.

Aim

The primary aim is to characterize the relationship between CATI activation time (time between case presentation at a cholera treatment facility and the start of the CATI intervention) and cholera incidence in the area covered by CATI interventions. Secondary aims include:

• Document procedures of implementing CATIs and develop recommendations to maximize their impact in future cholera outbreaks.
• Describe the integration of water, sanitation, and hygiene (WASH) and health activities delivered via CATI.
• Characterize the relationship between CATI completeness (in terms of coverage within the specified geographic area and activities implemented within households) and incidence of new cholera cases.
• Estimate CATI effectiveness using secondary parameters (e.g. reported diarrheal incidence, free chlorine residual (FCR) in the drinking water sample, and knowledge and practices to prevent cholera transmission).
• Document coordination mechanisms between Ministries, United Nations (UN) agencies, Clusters, and non-governmental organizations (NGOs) and develop recommendations for coordination in future responses.

Study Design

The proposed research will be conducted in future cholera outbreaks that take place in recognized humanitarian contexts in at least two different countries; locations will be selected based on where cholera outbreaks occur and the presence of a CATI implementing partner.  Organizations that frequently implement CATI interventions during cholera response that have agreed to partner with JHSPH include Action Against Hunger, Solidarités International, and Medair. Countries with humanitarian emergencies that are at high risk of cholera outbreaks include Democratic Republic of the Congo, Nigeria, Ethiopia, Mozambique and Yemen, though it is possible that other humanitarian contexts may serve as a research location if a cholera outbreak occurs and one of the aforementioned implementing partners responds with a CATI intervention.

The JHSPH IRB approval has classified this study as Non-Human Subjects Research.   Government or IRB approval will be attained prior to conducting the research.

The research team will be present at the site as soon as possible after the first cholera case has been documented and begin data collection as soon as feasible. If travel to the study location is not feasible for security reasons, the JHSPH research team will conduct the study remotely through the partner organization that is providing on-the-ground CATI response to the cholera outbreak.

Because the aim of the research is to evaluate CATIs as delivered by NGOs in response to a cholera outbreak, a randomized design is not possible. Thus, we will rely on comparison groups that will occur naturally, according to the outbreak size and capacity of the response organization. This will necessitate a flexible sampling approach.

We anticipate the primary comparison will be rapid vs. delayed CATI implementation (e.g. end stage of outbreak); however, it is also possible that areas with no CATI implementation could be used as a comparison group [in outbreaks where there is insufficient capacity to respond to all cases].  Additional points of comparison may include the delay between case presentation and CATI implementation:  e.g. CATI implemented within 24h, in 2 days, in 3 days, in 4 days, etc.

The proposed research is an observational study of cholera interventions implemented by NGOs in response to cholera outbreaks (i.e. no intervention is proposed).  The study will include the following components:

• Observation of CATI delivery
• Key informant interviews: 1) NGO staff members delivering the CATI intervention to characterize perceived strengths and weakness of the intervention, household selection, logistical processes and implementation challenges; 2) Humanitarian response managers from the partner NGO, UN agencies, national governments and other organizations engaged in the cholera response to ascertain perceptions of the response, coordination and CATI delivery and implementation
• Cholera treatment facility line lists: Information from cholera line lists is used to plan CATI interventions, where each individual on the line list (i.e. a cholera case) receives a household visit from a CATI team. The JHSPH study team will request line lists from health facilities [which may be augmented by the study team] to evaluate coverage of CATI interventions.
• Follow up survey: The household follow up survey will be conducted approximately 14 days after the presentation of the suspected cholera case at a cholera treatment facility. The exact sampling approach will depend on the density of housing in the community and the CATI implementation strategy. Household surveys will enquire about receipt of the CATI intervention, household composition, incidence of diarrhea and diarrhea care seeking among household members in the period since CATI implementation (or case presentation if there was no CATI), knowledge and practices of hygiene behaviors and observation of free chlorine level (FCR) in stored drinking water.

Cholera continues to pose a major global public health threat and is a marker of inequality and poverty as it reflects the lack of access to basic water and sanitation infrastructures. The risk of the spread of cholera is particularly high in humanitarian settings and fragile contexts.

Cholera transmission risk is higher for cholera case household members and nearby households. Mass interventions to contain cholera outbreaks are not resource efficient.  Preventive interventions targeting cholera case-households and neighbors have been found effective in past outbreaks. These interventions are often referred to as case area targeted interventions (CATIs). CATIs predominantly include water, sanitation, and hygiene (WASH) activities but can also include epidemiological surveillance, and health (clinical) services, primarily oral vaccination and antibiotic chemoprophylaxis.

There are limited studies on the best practices and effectiveness of CATIs in humanitarian settings.   This study aims to identify those factors that support optimal delivery and interventions of these CATIs for cholera reduction in humanitarian settings and fragile states.  The study design centers around observing the CATI activities of partner organizations as they respond to a cholera outbreaks in known humanitarian or fragile settings.

There is limited evidence studying the mechanisms, composition, interventions, timing, effectiveness of CATIs in humanitarian settings. This proposed research for CATI in humanitarian settings will focus on variations in CATI implementation and timing, monitoring and evaluation, and coordination and integration with the aim of expanding available evidence that can be used to inform the development of operational guidance for CATI interventions in cholera response.

Cholera remains a persistent global health problem that can be controlled by appropriate water and sanitation and oral cholera vaccination. Our project aims to support the geographic targeting of cholera control interventions with four key objectives:

• maintenance of a global database of cholera surveillance data which can be used by countries and GTFCC stakeholders to access centralized data sources and understand the country and regional cholera epidemiology;
• development of a statistical mapping pipeline, which produces high resolution global maps of cholera burden;
• provision of technical epidemiological and modeling support to countries and NGOs in cholera control;
• participation in GTFCC working groups to develop evidence-driven guidance related to cholera surveillance and elimination, targeting OCV campaigns, and identifying cholera burden hotspots.

This project supports efforts to map the global burden of cholera through the maintenance of a global database of cholera incidence and mortality and the development of statistical modeling methods to produce high resolution maps of cholera burden. The study team is working to develop a user-friendly web interface to the cholera database to support country and GTFCC stakeholder access to centralized data sources, and the global burden maps serve as the foundation for many planning and intervention targeting activities such as strategic demand forecasts for OCV and hotspot identification.

Effective targeting of OCV campaigns and WASH interventions for cholera control requires knowledge of the highest burden areas worldwide. The global cholera database and mapping efforts resulting from this project support countries and GTFCC stakeholders in characterizing cholera epidemiology and targeting their cholera control efforts.

Oral cholera vaccination (OCV) has typically been used in responsive, outbreak response settings, but growing vaccine supply and efforts to promote cholera control planning at national scales have led to more frequent use of preventive vaccination campaigns. The Vaccine Impact Modelling Consortium coordinates a multi-modeling effort to estimate the global impact of vaccines for several vaccine-preventable diseases. This work will expand on an existing OCV modeling framework to project the impact of multiple scenarios of global cholera vaccination campaigns, inform strategic planning for vaccine supply and vaccine demand and underscores the importance of the effective targeting of OCV campaigns. An R package will be developed to make the model more accessible and flexible for other users and policy questions.

This research aims to develop a flexible vaccine impact model that can project the global impact of oral cholera vaccination campaigns under different sets of planning scenarios.

The modeling framework that results from this project can be used to estimate the impact of cholera vaccination campaigns and advocate for increases to OCV campaign funding and supply.

In this project, we completed a systematic review of published and gray literature to assess the impact of WASH interventions in disease outbreaks in emergencies.

This work summarized the evidence on WASH and cholera, and identified “commonly implemented but severely under-researched” gaps.

Introduction

Cholera remains a frequent cause of outbreaks globally, particularly in areas with inade- quate water, sanitation and hygiene (WASH) services. Cholera is spread through faecal- oral routes, and studies demonstrate that ingestion of Vibrio cholerae occurs from consum- ing contaminated food and water, contact with cholera cases and transmission from contam- inated environmental point sources. WASH guidelines recommending interventions for the prevention and control of cholera are numerous and vary considerably in their recommenda- tions. To date, there has been no review of practice guidelines used in cholera prevention and control programmes.

Methods

We systematically searched international agency websites to identify WASH intervention guidelines used in cholera programmes in endemic and epidemic settings. Recommendations listed in the guidelines were extracted, categorised and analysed. Analysis was based on consistency, concordance and recommendations were classified on the basis of whether the interventions targeted within-household or community-level transmission.

Results

Eight international guidelines were included in this review: three by non-governmental organi- sations (NGOs), one from a non-profit organisation (NPO), three from multilateral organisations and one from a research institution. There were 95 distinct recommendations identified, and concordance among guidelines was poor to fair. All categories of WASH interventions were featured in the guidelines. The majority of recommendations targeted community-level trans- mission (45%), 35% targeted within-household transmission and 20% both.

Conclusions

Recent evidence suggests that interventions for effective cholera control and response to epidemics should focus on case-centred approaches and within-household transmission. Guidelines did consistently propose interventions targeting transmission within households. However, the majority of recommendations listed in guidelines targeted community-level transmission and tended to be more focused on preventing contamination of the environment by cases or recurrent outbreaks, and the level of service required to interrupt commu- nity-level transmission was often not specified. The guidelines in current use were varied and interpretation may be difficult when conflicting recommendations are provided. Future editions of guidelines should reflect on the inclusion of evidence-based approaches, cholera transmission models and resource-efficient strategies.

Cholera is a diarrhoeal disease caused by ingestion of the pathogenic bacteria Vibrio cholerae. Cholera is spread to susceptible individuals via the faecal-oral routes of transmission from consuming contaminated water and food, contact with cholera cases and from a contaminated environment. Water, sanitation and hygiene (WASH) interventions such as improved water sources, sanitation and hygiene measures can prevent and control the disease. While this is widely accepted, and demonstrated in Europe and the Americas which have been cholera free for decades after sanitary improvements, there is a paucity of evidence to support which WASH interventions are most relevant in cholera-affected populations today.

Guidelines for the implementation of WASH interventions in cholera epidemic and endemic settings have been written by numerous organisations and vary considerably. Whilst appropriate cholera response will be specific to geographical and social context, it is important that the guidelines are informed by the best possible and available evidence.

A total of eight guidelines were identified and 95 recommendations extracted from the guidelines. These were categorised and analysed for their consistency, concordance and according to current cholera transmission models. This paper details the included recommendations from guidelines and recommended actions to improve future guideline development by international organisations.

It may encourage change to guidelines or use of evidence in future cholera WASH guidelines

Oral cholera vaccines (OCV), administered in two doses, have emerged recently as a powerful tool for short-term outbreak control. When resources are limited, single-dose vaccination has been used as a way to stretch the supply, however, previous studies have shown that a single dose of vaccine is less effective, and wanes faster. In addition, studies have shown reduced effectiveness of the OCV in children under five years old, who are disproportionally affected by cholera. Determining who, how, and when to vaccinate are pressing decisions that public health officials usually take during an unfolding epidemic, often resulting in a sub-optimal use of resources. We will use mathematical models paired with optimization algorithms to determine optimal vaccine allocation, thereby providing public health officials with an evidence-based rationale for vaccine distribution.

Our specific aims are:

• To construct data-driven mathematical models of cholera transmission, infection and vaccination.
• To determine optimal vaccine allocation strategies.

This research will benefit countries with scarce resources for which making the best use of each dose of vaccine is a top priority.”

Cholera is an acute diarrheal disease. If left untreated, it can be fatal within hours. Oral cholera vaccines, administered in two doses, are a powerful tool for short-term control. When resources are limited, single-dose vaccination has been used as a way to stretch the supply. However, single-dose vaccination is less effective. In addition, cholera vaccines are less effective in young children, who are disproportionally affected by the disease. Decision makers are left with choices: vaccinating with one or two doses; vaccinating those who will benefit the most or those who are the most at risk. Determining who, how, and when to vaccinate are decisions that public health officials usually take under immense pressure, often resulting in a sub-optimal use of the available resources. We propose to use mathematical models paired with optimization algorithms to determine optimal vaccine allocation, thereby providing public health officials with an evidence-based rationale for vaccine distribution.

This project will provide a quantitative framework for OCV allocation, thereby providing decision makers with evidence-based tools for vaccine prioritization.

A rapid diagnostic test (RDT) that is simple, sensitive and specific would be highly valuable for the early confirmation of cholera outbreaks and for hotspot mapping in endemic settings. The current diagnostic tests for cholera, stool culture or RDTs are either requires ~72 hours in a good laboratory or the sensitivity and specificity are not optimal and varies.

We developed a novel RDT assay “Cholera-rapid LAMP based RDT (C-RLDT)” which is simple, rapid (<1hour), directly from stool, sensitive, specific, cold chain free, easy to interpret and inexpensive. This assay targets V. cholerae (ctxA and O1 rfb gene) using isothermal amplification. The limit of detection is similar to quantitative PCR. Our preliminary data with stool samples from endemic countries showed C-RLDT has high sensitivity and specificity compared to PCR and culture method. C-RLDT is capable of detecting cholera in water samples without enrichment.

We propose validating C-RLDT in comparison with culture, Crystal VC® and PCR and determining the operational performance and feasibility of implementing C-RLDT in District clinics as well as in a field setting when outbreaks occur in remote areas in Uganda, Nigeria and Bangladesh. We also propose to determine the validity of C-RLDT in detecting V. cholera from water.

We developed a simple and rapid diagnostic assay “C-RLDT” for the detection of cholera which could be applied to resource-poor settings. This assay is sensitive like PCR and specific and could detect cholera in stool and water. We aim to evaluate the performance and feasibility of the implementation of C-RLDT in Uganda, Nigeria and Bangladesh.

If this project is successful, C-RLDT could be integrated in the National cholera control plan in the cholera endemic countries.

Bangladesh remains endemic for cholera, which experiences biannual outbreaks with additional epidemics seen during times of floods, cyclones or any natural disaster [1, 2]. It affects all age groups with the majority of fatal cases occurring in children [3-6]. Therefore, immunization against cholera remains an important public health component in the prevention and control of the disease [6]. A problem that may be a stumbling block in the path is that the oral cholera vaccine (OCV) is in short supply globally and only about 2-3 million doses are produced each year. In Bangladesh alone we anticipate that 170 million doses will be needed in a 5 year time frame if only high risk populations are targeted. Globally for the rest of Asia and Africa as well as for Haiti, millions of doses of vaccine is needed for control of endemic and epidemic cholera. The global demand for the vaccine is therefore high and the good news is that, there is now provision for local production of over 50 million doses in Bangladesh. With this prospect in view, planning for prevention of cholera by use of OCV, it may be possible to decrease the burden of the disease in Bangladesh.

Knowledge gap

More evidence is needed to address uncertainties around the cholera disease burden, as well as the impact, feasibility, and cost-effectiveness of various vaccination strategies against cholera, to add to the existing knowledge base. A special need for acquiring field evidence of these vaccine attributes in settings with endemic cholera, which account for a very large fraction of the global cholera disease burden, is also recognized [7].

There is a great need for identify financing mechanisms for introduction of vaccination against cholera. All these efforts will hopefully decrease the burden due to cholera which has both health and financial burden on the country. Studies have shown that the cost of hospitalization and illness to the patient and the family is around ten times higher than the cost of vaccine [8, 9].

A countrywide surveillance is needed which will help to identify the disease burden in the country, so as to plan appropriate treatment and preventive measures.

Relevance

Bangladesh needs to plan strategies for introduction of a locally produced oral cholera vaccine in Bangladesh. Thus clear information from national stakeholders on the cholera investment strategy for Bangladesh is needed based on which future plans can be made. In addition, information i s needed on the strategies for vaccination and areas which need to come under coverage. With the availability of a locally produced vaccine in Bangladesh, financing plans and funders will be needed to materialize the immunization plans for people with OCV.

Objectives

The objectives of the proposal are as follows:

• Build a plan (including surveillance of high risk areas) and identify strategies for the introduction of OCV in Bangladesh by developing the cholera investment case based on the present scenario.
• Identify a financing plan for the introduction of the locally produced vaccine in Bangladesh in the short term.

Methods

We will update the current cholera investment case study on cholera vaccination for Bangladesh which was previously prepared by International Vaccine Institute (IVI) in 2009. This will provide a useful evidence based guide to policy makers in Bangladesh in making decisions about the use of OCV as well as to the global health community in considering technical and financial support for cholera vaccine introduction. The information on where and whom to vaccinate will also be obtained to accumulate information by working on nationwide cholera surveillance from all over Bangladesh. Surveillance will be conducted in different government and non government hospitals and medical colleges in sites already known to have diarrheal disease burden.

Bangladesh remains endemic for cholera, which experiences biannual outbreaks with additional epidemics seen during times of floods, cyclones or any natural disaster. It affects all age groups with the majority of fatal cases occurring in children. Therefore, immunization against cholera remains an important public health component in the prevention and control of the disease. In Bangladesh alone we anticipate that 170 million doses will be needed in a 5 year time frame if only high risk populations are targeted. The global demand for the vaccine is high and the good news is that, there is now provision for local production of over 50 million doses in Bangladesh. With this prospect in view, planning for prevention of cholera by use of OCV, it may be possible to decrease the burden of the disease in Bangladesh.

Bangladesh needs to plan strategies for introduction of a locally produced oral cholera vaccine in Bangladesh. Thus clear information from national stakeholders on the cholera investment strategy for Bangladesh is needed based on which future plans can be made. In addition, information is needed on the strategies for vaccination and areas which need to come under coverage. With the availability of a locally produced vaccine in Bangladesh, financing plans and funders will be needed to materialize the immunization plans for people with OCV.

Therefore, the objectives of the current study are as follows:

• Build a plan (including surveillance of high risk areas) and identify strategies for the introduction of OCV in Bangladesh by developing the cholera investment case based on the present scenario.
• Identify a financing plan for the introduction of the locally produced vaccine in Bangladesh in the short term.

Different data will be used to develop and recommend up to 3 optimal strategies for introduction of Oral Cholera vaccine (OCV) with associated vaccine demand, budget and health impact. For this recommendation we will communicate with different level of Government of Bangladesh (GoB) and other internal and external stakeholders with our preferred feasible strategy for introduction of vaccine.

Cholera, an acute watery diarrheal disease, caused by toxigenic strains of the bacterium Vibrio cholerae O1 and O139, causes an estimated over 2.9 million cases and over 95,000 deaths annually in cholera endemic countries alone and frequent epidemics in other settings with poor water and sanitation infrastructure. Global estimates range from 1.4-4.8 million cases and 28,000 – 142,000 deaths every year 1. The disease is characterized by acute onset watery diarrhea leading to rapid dehydration and death, if not promptly treated.

Recently a conflict has been conducted in the Rakhine province of Myanmar. During this conflict over 500,000 Rohingya refugees (URMN) have recently been displaced and entered into Cox’s Bazar district in Bangladesh. Among newly arrived displaced people, 60% are women and children living in conditions where public health facilities are lacking. These people are probably not primed and exposed to cholera and the prevailing conditions are high risk for cholera. In the recent past, e.g in Yemen, South Sudan, Haiti and other countries, lack of WaSH and public health facilities have led to large epidemics with high numbers of cholera cases and death. Considering this risk assessment international co-ordination group (ICG) of WHO allocate 900,000 oral cholera vaccines from WHO stockpile to deploy among the refugees.

The prevention of cholera has become a high priority in the global community. Immunization with OCV is the most effective means of preventing cholera infection and its consequence. The World Health Organization (WHO) has warned of a growing risk of a cholera epidemic at makeshift refugee camps in Bangladesh where hundreds of thousands of Myanmarese Rohingya Muslim refugees are sheltered in dire conditions. The camps did not have safe drinking water and lacked sufficient hygiene; filthy water and feces flowed openly through the camps. Risk of waterborne diseases is high, especially there is very high risk of cholera in these camp. Interventions like vaccination are being scaled-up as the situation remains critical and challenging.

The study of ShanChol OCV on Unregistered Myanmar Nationals (URMN) in children and adults will be able to give information regarding the safety and immunogenicity of the vaccine in URMN subjects. This information will be important for proceeding with the cholera vaccination in the refugee population of same socioeconomic structure in future.

Hypothesis

Oral Cholera vaccine (OCV) is immunogenic in different age groups of Unregistered Myanmar Nationals (URMN).

Objectives

The objective of this study is to evaluate the immunogenicity of OCV among healthy Unregistered Myanmar Nationals (URMN) in Bangladesh.

Methods

This will be cross sectional study on a total of 226 healthy Unregistered Myanmar Nationals (URMN). There will be three age cohort which will consist of 80 participants for age 1-5 yrs, 63 participants for age 6-17 yrs and 83 for age 18 yrs and above, with a total of 226 participants. Blood will be taken before and after OCV administration.

Outcome measures/variables

To evaluate the immunogenicity of OCV among Unregisterd Myanmar Nationals (URMN).
The immunogenicity component will be measured by assessing the sero-conversion rate of vibriocidal antibodies after vaccination with OCV to Vibrio cholerae O1.

Cholera, an acute watery diarrheal disease, caused by toxigenic strains of the bacterium Vibrio cholerae O1 and O139, causes an estimated over 2.9 million cases and over 95,000 deaths annually in cholera endemic countries alone and frequent epidemics in other settings with poor water and sanitation infrastructure. The disease is characterized by acute onset watery diarrhea leading to rapid dehydration and death, if not promptly treated.

Among newly arrived displaced people, 60% are women and children living in conditions where public health facilities are lacking. These people are probably not primed and exposed to cholera and the prevailing conditions are high risk for cholera. In the recent past, e.g in Yemen, South Sudan, Haiti and other countries, lack of WaSH and public health facilities have led to large epidemics with high numbers of cholera cases and death.

The study of ShanChol OCV on FDMN in children and adults will be able to give information regarding the safety and immunogenicity of the vaccine in URMN subjects. This information will be important for proceeding with the cholera vaccination in the refugee population of same socioeconomic structure in future.

Therefore, the objective of this study is to evaluate the immunogenicity of OCV among healthy Forcibly Displaced Myanmar Nationals (FDMN) in Bangladesh.

By evaluating the immune responses of OCV among Forcibly Displaced Myanmar Nationals (FDMN), we can compare the immune responses between Bangladeshi population and FDMN. We can also assess the sero-conversion rate of vibriocidal antibodies after vaccination with OCV to Vibrio cholerae O1.

Cholera continues to be a major cause of morbidity and mortality in low-income countries including Bangladesh. It is estimated that over 2.9 million cases and over 95,000 deaths occurs annually in cholera endemic countries alone and frequent epidemics happened in other settings with poor water and sanitation infrastructure. (1) The overall morbidity for cholera remains high. A global stockpile of OCV has been created by WHO in 2013 for epidemic and outbreak settings. (2) The disease is characterized by acute onset of watery diarrhea leading to rapid dehydration and death, if not promptly treated. From August, 2017 Rohingya Myanmar Nationals (RMN) have been influxed to Bangladesh through Cox’s Bazar border of Bangladesh. They are staying at the camps of two different upazilas (Teknaf and Ukhiya) of Cox’s Bazar. According to the latest assessment, more than half (52%) of the total Rakhine state’s population has no access to the improved sanitation facility. Also, around 45% of the population has not access to or is not using improved water supply facility according to the SDG standards.(14) Considering this risk assessment international co-ordination group (ICG) of WHO allocate 900,000 oral cholera vaccines from WHO stockpile to deploy among the RMN.

The prevention of cholera has become a high priority in the global community . Immunization with OCV is the most effective means of preventing cholera infection and its consequence. The World Health Organization (WHO) has warned of a growing risk of a cholera epidemic at the Rohingya camps in Bangladesh where people are sheltered in dire conditions. The camps did not have safe drinking water and lacked sufficient sanitation and hygiene; filthy water and feces flowed openly through the camps. Risk of waterborne diseases is very high, especially there is increasingthe risk of cholera in these camp. Moreover, according to a total number of 782 cases with 11 deaths have been reported in 2016 from Myanmer when the case fatality rate was 1.4%.(9) Interventions like vaccination are being scaled-up as the situation remains critical and challenging. But information related to vaccine effectiveness under this humanitarian condition is lacking

Relevance

The study of Shanchol OCV on Rohingya Myanmar Nationals (RMN) in children and adults will be able to give information regarding the effectiveness of vaccine in RMN subjects. This information will be important for proceeding with the cholera vaccination in the refugee population of same socioeconomic structure in future.

Objectives

The objective of this study is to determine the effectiveness of OCV in a test-negative case control design among Rohingya Myanmar Nationals (RMN) in Bangladesh.

Methods

This study will be conducted in Ukhiya upazila of Cox’s Bazar district. Here we would like to conduct the study through a test-negative case-control design. The participants will be the RMN who will come to the treatment center for seeking management of acute watery diarrhea (AWD). The stool or rectal swab of all participants will be tested. The cholera positive participants will be considered as cases whereas the cholera negative will be considered as control. The vaccine effectiveness will be measured by comparing the ratio of odds of vaccination in the cholera positive patients and odds of vaccination in the cholera negative patients.

Outcome measures/variables

The vaccine effectiveness will be measured by comparing the ratio of odds of vaccination in the cholera positive patients and odds of vaccination in the cholera negative patients.

Cholera continues to be a major cause of morbidity and mortality in low-income countries including Bangladesh. It is estimated that over 2.9 million cases and over 95,000 deaths occurs annually in cholera endemic countries alone and frequent epidemics happened in other settings with poor water and sanitation infrastructure. The overall morbidity for cholera remains high. A global stockpile of OCV has been created by WHO in 2013 for epidemic and outbreak settings. The disease is characterized by acute onset of watery diarrhea leading to rapid dehydration and death, if not promptly treated. From August, 2017 Forcibly Displaced Myanmar Nationals (FDMN) have been influxed to Bangladesh through Cox’s Bazar border of Bangladesh. They are staying at the camps of two different upazilas (Teknaf and Ukhiya) of Cox’s Bazar. According to the latest assessment, more than half (52%) of the total Rakhine state’s population has no access to the improved sanitation facility. Also, around 45% of the population has not access to or is not using improved water supply facility according to the SDG standards. Considering this risk assessment international co-ordination group (ICG) of WHO allocate 900,000 oral cholera vaccines from WHO stockpile to deploy among the FDMN. Therefore the objective of this study is to determine the effectiveness of OCV in a test-negative case control design among Forcibly Displaced Myanmar Nationals (FDMN) in Bangladesh.

“The vaccine effectiveness will be measured by comparing the ratio of odds of vaccination in the cholera positive patients and odds of vaccination in the cholera negative patients.
”

In 2012, the 65th World Health Assembly (WHA) declared the completion of poliomyelitis (polio) eradication to be a programmatic emergency for global public health. Cholera, another life-threatening infectious disease, is highly endemic and epidemic in many of the same parts of the world affected by polio.

Currently, no studies have been conducted to determine if any of the OPV and OCV can be co-administered without impacting the immunogenicity of either vaccine. Data on co-administration of the currently available whole-cell killed OCVs with other oral vaccines, specifically, oral polio vaccines is lacking.

Effective immunization with high coverage remains the key for interruption of polio transmission, and vaccination is a vital complementary strategy for cholera control. Given that OPV campaigns in most polio priority settings target a largely overlapping population as OCV campaigns, the results of this study are crucial and highly relevant for OPV-OCV vaccine administration policies. If able to be co-administered safely and effectively, combined OPV-OCV campaigns may potentially outline large cost-savings and eliminate potentially redundant administration costs and improve adherence.

Co-administration of oral polio vaccine (OPV) and oral cholera vaccine (OCV) will not decrease immunogenicity of either vaccine among children 1 – 3 years old.

Objectives

Primary

• To compare seroconversion for OPV types P1 and P3 when administered alone versus when administered with OCV on day 28 and 56 after vaccination.
• To compare vibriocidal antibody response (based on a ≥ 4-fold rise) to OCV when administered alone versus when co-administered with OPV on day 28 and day 56 after vaccination.

Secondary

• To determine safety of co-administration of OPV with OCV compared to OPV or OCV alone.

Methods

We propose to conduct an open-label, randomized controlled study in Dhaka, Bangladesh, among healthy children aged 1 – 3 years old who have received < 3 doses of OPV and has not received any dose of IPV or OCV at any time before enrolment based upon immunization card record or history from parents.

Outcome measures/variables

Primary

• Anti-polio virus antibodies type 1 and type 3 microneutralization titer when OPV and OCV are administered separately, and when given together.
• Vibriocidal antibody response to V. cholerae O1, serotype Ogawa and Inaba when OPV and OCV are administered separately and when given together.

Secondary

• Number of adverse events and serious adverse events between OPV and OCV when given alone versus when given concomitantly.

Effective immunization with high coverage remains the key for interruption of polio transmission, and vaccination is a vital complementary strategy for cholera control. Given that OPV campaigns in most polio priority settings target a largely overlapping population as OCV campaigns, the results of this study are crucial and highly relevant for OPV-OCV vaccine administration policies. If able to be co-administered safely and effectively, combined OPV-OCV campaigns may potentially outline large cost-savings and eliminate potentially redundant administration costs and improve adherence. Therefore, the main objectives of the study are:

• To compare seroconversion for OPV types P1 and P3 when administered alone versus when administered with OCV on day 28 and 56 after vaccination.
• To compare vibriocidal antibody response (based on a ≥ 4-fold rise) to OCV when administered alone versus when co-administered with OPV on day 28 and day 56 after vaccination.

• Anti-polio virus antibodies type 1 and type 3 microneutralization titer when OPV and OCV are administered separately, and when given together.
• Vibriocidal antibody response to V. cholerae O1, serotype Ogawa and Inaba when OPV and OCV are administered separately and when given together.

Burden

Cholera remains a major global health problem, resulting in more than 100,000 deaths and several million cases annually. Bangladesh, which lies in the Ganges River Delta, is a hyper endemic country and has an estimated 300,000 cholera cases and over 4,500 deaths annually. In early 2020, the SARSCoV-2 pandemic shocked the world leading to over 43 million cases and over 1 million deaths globally by October 2020. In Bangladesh, by October 2020, there have been an estimated 400,000 cases and over 5,000 deaths. With the implementation of non-pharmaceutical interventions like social distancing, healthcare seeking behaviors have likely been affected resulting in the likely underestimation of both cholera and COVID-19 cases.

Knowledge gap

To meet the ambitious goals set by the WHO of reducing cholera as a public health threat by 2030 and reduce cholera in the hyper endemic setting of Bangladesh, improving our methods for counting cholera cases and infections is critical for control planning. At present, most cholera burden estimates are derived from passive clinical based surveillance, which only captures a portion of true cases and infections due to barriers to healthcare seeking. While we have recently developed methods to estimate V. cholera infection incidence at the population-level, some fundamental questions still remain on how to interpret this data in relation to clinical incidence. Furthermore, we know little about how the COVID-19 pandemic has affected healthcare seeking for cholera or what the seroprevalence of SARS-CoV-2 is in the population.

Relevance

Results from this study will improve our knowledge of cholera incidence in Bangladesh to aid the distribution of interventions like the oral cholera vaccine. Refining our methods for estimating cholera burden will additionally improve how we estimate cholera burden in other countries and estimate future vaccine demand. This study will also result in the estimation of the seroprevalence of SARSCoV- 2 infection in the study region in Bangladesh which will help inform the implementation of
interventions like vaccination and improve our understanding of how the COVID-19 pandemic has disrupted healthcare seeking behaviours.

Objectives

The primary objective of this study is to improve and refine our methods for estimating correlates of cholera burden from cross-sectional serosurveys though enhanced clinical surveillance of cholera at two healthcare facilities and through serial serosurveys. A secondary objective of this study is to better understand the maturity of the SARS-COV-2 epidemic in this population by measuring the prevalence of SARS-COV-2 antibodies in the population and estimating key individual-, household- and
community-level risk factors for infection.

Study Site

This study will be focused at two healthcare facilities, the Bangladesh Institute of Tropical Infectious Diseases (BITID) and the Sitakunda Upazila Health Complex (UHC), and their catchment population, the Sitakunda Upazila within the Chittagong District in South Eastern Bangladesh. Historical clinical and serologic surveillance from the district suggest that cholera incidence is relatively high compared to other parts of Bangladesh (e.g.,1.15 times the seroincidence than the mean for the country based on a serosurvey conducted in 2015) with two seasonal peaks in cholera admissions, the larger one typically starting in March and the smaller one towards the end of the calendar year. Clinical surveillance data from 2014-2018 illustrate that a greater number of patients with acute watery diarrhea visit BITID from April to June; on average approximately 4,000 individuals seek care at BITID for acute watery diarrhea within a single year. We anticipate that within a 18-month period,
approximately 9,000 patients will seek care at both BITID and the Sitakunda UHC.

Cholera remains a major global health problem, resulting in more than 100,000 deaths and several million cases annually. Bangladesh, which lies in the Ganges River Delta, is a hyper endemic country and has an estimated 300,000 cholera cases and over 4,500 deaths annually. In early 2020, the SARS-CoV-2 pandemic shocked the world leading to over 43 million cases and over 1 million deaths globally by October 2020. In Bangladesh, by October 2020, there have been an estimated 400,000 cases and over 5,000 deaths. With the implementation of non-pharmaceutical interventions like social distancing, healthcare seeking behaviors have likely been affected resulting in the likely underestimation of both cholera and COVID-19 cases.

The primary objective of this study is to improve and refine our methods for estimating correlates of cholera burden from cross-sectional serosurveys though enhanced clinical surveillance of cholera at two healthcare facilities and through serial serosurveys. A secondary objective of this study is to better understand the maturity of the SARS-COV-2 epidemic in this population by measuring the prevalence of SARS-COV-2 antibodies in the population and estimating key individual-, household- and community-level risk factors for infection.

Our primary study outcome is the change in seroincidence between the first and third serosurvey to capture changes in cholera incidence over the course of the typical high and low season at the study site. Our secondary outcome is the prevalence of anti-SARS-CoV-2 antibodies among individuals in the first serosurvey. We will explore the associations between seropositivity (for cholera and SARS-COV-2) and different individual-, household- and community-level risk factors collected in the surveys, including WASH attributes and factors like population density, travel time (to the nearest city), distance to a major water body, community water and sanitation coverage, and poverty.

While there is ample evidence on the direct protection conferred by killed whole-cell oral cholera vaccines (OCV), there is limited evidence documenting the population-level impacts of mass vaccination on infection rates, disease incidence and mortality both due to the limited number of mass campaigns that have been conducted in cholera-endemic areas and due to the generally weak clinical surveillance systems for cholera. As more and more vaccines become available and endemic hotspots plan to use OCV, evidence on the population level impacts of mass vaccination are needed to help set expectations for the role OCV can play in short- to medium-term global reductions in cholera. Eastern Democratic Republic of Congo provides a unique setting to study the impacts of mass vaccination given the reporting of cholera cases throughout the year and the ambitious plans by the Ministry of Health to substantially reduce cholera burden in the years to come through improvements in water and sanitation and the use of OCV.

Relevance

Results from this study will allow for a better estimation of the impact of mass oral cholera vaccination campaigns deployed in Uvira (South Kivu) on the incidence of confirmed clinical cholera and mortality. To further understand both direct and indirect effects of vaccination while more explicitly accounting for changes in population movement, secular changes and waning vaccine protection, we will fit dynamic transmission models to data from Uvira. A better understanding of these effects will also aid in the country’s national plan for cholera elimination over 2018-2022.

Objectives

There are three main objectives of this study. The first is to estimate the impact of mass oral cholera vaccination campaigns deployed in the city of Uvira on the incidence of confirmed clinical cholera and cholera-related mortality from 2021 through 2026. The second is to describe V. cholerae contamination patterns and genetic diversity over time in patients, households, and the broader environment through microbiological analyses of clinical and environmental samples. The third and final objective is to describe changes in vaccine coverage, care seeking behavior, and serologically-derived V. cholerae infections rates in the city of Uvira from 2021 to 2026.

Methods and Outcome measures / Variables

This study has three main components; surveillance for medically attended cholera, follow-up studies in households of confirmed cholera cases with environmental surveillance and representative household surveys.

For clinical surveillance, systematic cholera confirmation through RDT, culture and qPCR will be continuously conducted over the study period at the primary sites in Uvira for diarrhea/cholera treatment; a cholera treatment centre (CTC) and cholera treatment unit (CTU).

For household follow-up studies, environmental sampling in households of confirmed cholera cases as well as matched controls, and at community water sources will be conducted by study staff in addition to laboratory testing for V. cholerae via culture-based and molecular methods.

Representative household surveys will be conducted each year, with blood collection done in a subset (3 of the years). Data on migration patterns, vaccine coverage, access to and use of WASH infrastructure, household mortality and other data will be collected from all participating individuals within households. We will test serum for a suite of antibodies related to previous V. cholerae O1 infection and use machine learning models to estimate seroincidence. ”

We aim to quantify the impact of the killed oral cholera vaccine (OCV) on cholera incidence and mortality over 6 years (2021-2026) in Uvira, Democratic Republic of Congo, a city with endemic cholera transmission. In addition, we hope to better understand how contamination patterns and genetic diversity of the cholera-causing bacteria change over time (pre- and post-vaccination) through analysis of clinical and environmental samples.

This study will help us better understand the impact of mass cholera vaccination programs to set expectations for decision makers and help understand when revaccination may be needed.

Burden

Beginning in Asia in 1961, the 7th cholera pandemic spread world-wide, reaching in Africa in 1970, and finally South America in 1991. A massive epidemic exploded in Peru in January 1991, spread rapidly from south to north of Latin America, and reached Mexico in June causing thousands of deaths. Since America was affected badly after about a century of no cholera, naturally the source of the disease was an enigma. Several studies in the past proposed contrasting views about the source, some arguing about a local source while others believed cholera to be an extension of 7th pandemic El Tor from Asia; although disease was rampant since 1991 and continuing throughout the continent causing morbidity and mortality in South and Central America.

Knowledge gap

A recent retrospective study on V. cholerae isolated from clinical and environmental sources in Mexico, between 1991 and 1997, confirmed both classical and El Tor biotypes with the latter presenting distinct genotypic and phenotypic traits including strains that had variants having a combination of classical biotype characteristics under the El Tor background. These results appeared in a sharp contrary to what has been proposed for the cholera in the Americas to be of Asian origin as El Tor was the only circulating biotype shown in Peru until recently. In order to further understand the evolutionary trends of bacteria causing endemic cholera in Mexico, we propose to carry out an extensive study on V. cholerae strains isolated from endemic cholera between 1998 and 2008. This study is vital for us to understand the evolutionary trend in terms of the prevalent sero-biotypes of V. cholerae to be able to develop a unified global model for intervention and preventive measures.
Relevance: Cholera is a pandemic disease claiming millions of lives globally. Efforts are being made to improve the understanding of cholera and V. cholerae associated with the disease globally. The America was affected badly after about a century of no cholera, and so very little is known about V. cholerae associated with the disease. The proposed study will generate important data on the phenotypic and genotypic traits of V. cholerae causing endemic cholera in Mexico during 1998 – 2008. The data obtained will help us to develop a unified global approach for intervention and preventive measure against cholera globally.

Hypothesis

After 1991 outbreaks in Latin America, cholera continues to be endemic in many countries of the Americas including Mexico. Our recent retrospective study on V. cholerae isolated between 1991 and 1997 showed the association of biotypes classical, El Tor, and El Tor variants with the endemic cholera in Mexico (Alam, et al., with H. Watanabe, M. Morita…A. Cravioto (JCM 2010). We hypothesis that the V. cholerae associated with endemic cholera is evolving independently in Mexico. The proposed follow-up study will generate important microbiological, molecular and phylogenetic data on V. cholerae causing endemic cholera in Mexico to be able to develop a unified global model for intervention and preventive measure against cholera globally.

Objectives

The aim of this study is to understand the latest status of cholera bacteria in Mexico, particularly to determine the prevalent sero-biotypes of V. cholerae and their clonal nature to develop a unified global approach for intervention and preventive measure against cholera world-wide.

Methods

V. cholerae isolated from endemic cholera in Mexico during 1998 – 2008 will be subjected to extensive phenotypic, molecular, and phylogenetic analysis. For this, we will involve serology, antimicrobial assay, multi-locus genome scanning (by simplex and multiplex PCR) and sequencing of targeted genes. DNA fingerprinting will be determined by molecular tools such as PFGE and the data will be analyzed by bionumeric software. Dendrograms will be generated by using appropriate computational tools.

Cholera is unheard of for a century from Latin America, and so is the V. cholerae. This sudy was designed to characterize V. cholerae associated with Latin American cholera in 1991 and subsequent years.

Better understanding of the phenotypic and gentypic characteristics will aid in deciding intervention and preventive measures against cholera.

Burden

Cholera has been well-established as a seasonal disease that varies in the patterns of infections. The seasonal outbreaks of cholera occurs in multiple endemic foci of Bangladesh, most showing a single annual peak like in other cholera affected regions of the world. However, cholera shows two distinct seasonal peaks, one before (March – May) and the other after (September – November) the annual monsoon [6] in Dhaka and Matlab, Bangladesh. V. cholerae has been established as an autochthonous flora of brackish waters and estuarine ecosystems [11] where the bacterium shares niche, and is found in association with plankton [12]. Although sea surface temperature has been shown to have a degree of correlation with the incidence of cholera in Bangladesh [13], little is known about how these factors contribute to the seasonal cholera outbreaks in the freshwater environments of Dhaka and Matlab, which are 50km apart, and 350 km away from the coast of Bay of Bengal. Historically, most major epidemics have originated in the coastal regions, including the O139 Bengal outbreaks that originated in the Bay of Bengal villages of India and Bangladesh. In Dhaka and Matlab, endemic cholera occurs in distinctive two-peak pattern, before and after the monsoon [1,14], although the diseases continues even beyond the defined seasons and can appear as off-season peaks affecting many.

Knowledge gap

In August 2007, Bangladesh suffered flooding, which was accompanied by a large diarrhea outbreak in Dhaka city just prior to the usual fall peak that followed. During this outbreak, the ICDDR,B Dhaka hospital treated a record number of cholera patients peaking at 1045 patients per day, with 70% suffering from severe dehydration. Although V. cholerae O1 ET was the etiological agent, the detail characteristics of the bacterium causing increasing severity of cholera including the natural factors driving the off-season epidemics remain important to be explored.

Relevance

This study will generate important data on the climate factors, and phenotypic (antibiogram), molecular, and phylogenetic characteristics of V. cholerae ET associated with the severe disease outbreak of seasonal and off-season cholera. The data will aid in formulating therapeutic intervention and preventive measures against the deadly disease.

Hypothesis

The seasonal and off-season cholera outbreaks have different hydro-climatic drivers in Bangladesh, and the increased severity of 2007 flood outbreak might be the result of fecal-oral transmission of hyper-infectious V. cholerae.

Objectives

• To study the phenotypic, molecular, and phylogenetic characteristics of V. cholerae associated with severe disease outbreak of seasonal and off-season cholera in 2007.
• To analyze the regional hydroclimatological data for over 30-35 years (1980s – 2018) to understand the natural driver(s) of cholera.

Methods

An estimated 1000 V. cholerae strains from seasonal and off-season cholera outbreaks in 2007 and in the subsequent years, up to 2018, would be included in this study. V. cholerae strains will be collected from routine 2% hospital surveillance samples at Dhaka hospital of icddr,b at an estimated number of 80 – 100 strains/year for phenotypic, molecular and phylogenetic analyses, including multilocus genetic screening by simplex and multiplex-PCR, sequence-typing of the genes (namely ctxB), pulsed-field gel electrophoresis (PFGE), and whole genome sequencing (WGS). No patient data will be collected in this study other than the date of hospital enrolment to keep temporal records of the infections. Role of climate and related factors e.g., hydroclimatological data such as annual water flow in the major basins, temperature, rainfall, humidity etc. associated with the unusual incidence of cholera cases suffering from severe disease will also be determined.

This study was designed to characterize V. cholerae responsible for the seasonal and off-season cholera outbreaks in Dhaka.

Unveiling the clonal type responsible for seasonal and off-season cholera outbreaks is crucial to decide intervention and preventive measures against cholera.

Burden

Cholera, a scourge, remains one of the major causes of morbidity and mortality world-wide. The global burden of cholera is estimated to be about 3-5 million cases each year with an estimated deaths of 100,000 to 120,000, majority occurring in the developing countries of Asia and Africa. The causative agent of cholera, Vibrio cholerae, is a genetically versatile bacterial species for which more than 200 serogroups have been identified and for which significant lateral transfer of genes has been demonstrated. Pandemic cholera is generally caused by toxigenic strains of V. cholerae serogroups O1 and O139. V. cholerae O1 has been divided into two biotypes, classical (CL) and El Tor (ET), differing primarily in phenotypic traits and distinct signature genome sequences. Of seven cholera pandemics recorded since 1817, the sixth and presumably the earlier pandemics have been caused by CL biotype, which was replaced in the 1980s by ET biotype initiating the currently ongoing seventh cholera pandemic. The Ganges Delta of the Bay of Bengal has been the traditional home where cholera is endemic for centuries. Although V. cholerae has been an integral part of the bacterial community sharing niche in the estuarine ecosystem of Bay of Bengal, little is known about the aquatic life cycle of V. cholerae, particularly how a pandemic pathogen emerges from the naturally occurring benign population residing this historic ecosystem.

Knowledge gap

Despite intensive research efforts have been made to understand the epidemiology and ecology of V. cholerae, of its physiology and mode of infection in laboratory and in animal model systems, our knowledge is very limited and we still do not fully understand the molecular basis of pathogenicity of the bacterium and why cholera is a seasonal disease, and how a pandemic pathogen takes shape from among the diverse population occurring in the historical niche of the Bay of Bengal estuaries and spread.

Hypothesis

Since cholera has been endemic in the coastal villages of Bay of Bengal (Bangladesh), we hypothesize that the toxigenic V. cholerae responsible for the century-old Asiatic cholera is an integral part of the estuarine vibrio community that are influenced by the local climate, and includes ecological types (ecotypes) unique for this ecosystem.

Objectives

Our primary aim is to:

• Study the population structure (ecotypes) of V. cholerae occurring in the estuarine aquatic ecosystems of the Bay of Bengal

Our secondary aim is to:

• Understand how the naturally occurring toxigenic V. cholerae population (ecotypes) responds to the seasonal change in the regional climate to initiate seasonal cholera.
• Determine virulence potential of epidemiologically significant V. cholerae and related enteric pathogens of environmental and clinical origin by molecular and animal model assays.
• Decipher the transmission of epidemiologically significant V. cholerae regionally, and beyond. For this, we will compare the population structure, virulence and related molecular traits of V. cholerae occurring in the Bay of Bengal estuaries with that of the US east coast (Chesapeake Bay and Falmouth MA), for example.
• Determine antimicrobial resistance (AMR) of environmental and clinical strains of V. cholerae and related enteric pathogens.

Methodologies

V. cholerae (n=2100) would be isolated by culture method from water samples collected monthly from 8 selected Bay of Bengal estuarine pond and river sites located at the cholera-endemic coastal villages of Potuakhali, Bangladesh. Water samples would be collected aseptically in sterile Nalgene bottle and transferred to icddr,b Dhaka hospital for microbiological analysis. “

We designed this study to monitor and characterizing naturally occurring V. cholerae initiating seasonal (endemic) cholerea in Bangladesh.

Genetic tracking of Vibrio cholerae in its natural aquatic environments to provide insights that will aid prediction and preventive measures against upcoming cholera in Bangladesh

Burden

Cholera, a scourge, causes significant morbidity and mortality world-wide, especially in the Ganges Delta of Bangladesh. The global burden of cholera is estimated to be about 3-5 million cases each year with an estimated deaths ranging from 100,000 to 120,000, and majority occurring in the developing countries of Asia and Africa, including Bangladesh. Despite intense researches have been done on the epidemiology and ecology of V. cholerae, including its virulence, mode of infection in laboratory and in animal model systems, our knowledge is limited in regards the vibriophages of their role in the V. cholerae pathogenicity, seasonality of the disease cholera, and the ecology of the bacterium in the natural estuarine environments of Bangladesh.

Knowledge gap

Vibriophages play a critical role in pathogenicity and in controlling the seasonal outbreaks of cholera in Dhaka, Bangladesh, although research on the role of vibriophages on the V. cholerae pathogenicity, seasonality of the disease cholera, and the ecology of the bacterium responsible for endemic cholera in the coastal and estuarine environments remains an important area to be explored.

Relevance

Vibriophages have been known to play an important role in virulence of V. cholerae and in controlling the seasonal outbreaks of cholera; however, our knowledge is limited about how phages contribute to V. cholerae pathogenicity, seasonality of the disease cholera, and the ecology of the bacterium in estuarine villages of Bangladesh. The study findings will be useful for designing therapeutic intervention and preventive measures against deadly disease cholera.

Hypothesis

We hypothesize that the vibriophages present in the coastal and estuarine environment play an important role on the V. cholerae (O1, O139, and non-O1/O139) pathogenicity, seasonality of the disease, and the ecology of the bacterium responsible for endemic cholerain the coastal and estuarine aquatic environments of the Bay of Bengal, Bangladesh.

Objectives

This study aims to understand the genetic diversity of specific vibriophages playing important role in the pathogenicity, epidemiology and ecology of V. cholerae in the coastal and estuarine environments of Bangladesh.

Methods

Both vibriophages and toxigenic V. cholerae (O1, O139, and non-O1/O139) will be collected from cholera patients and from estuarine environment of Mathbaria for two years, during 2016-2018. Environmental parameters such as temperature, turbidity, pH, salinity, and conductivity will be measured on site, and both stool and water samples will be collected, cryo-protected and stored in -20oC freezer for vibriophage and V. cholerae isolation following enrichment in APW broth. Samples will be transported to icddr,b Dhaka hospital for further analysis. V. cholerae isolates and an aliquot of each sample will be shipped to USA for vibriophage isolation and critical characterizations by sequencing both. Vibriophage and toxigenic V. cholerae will also be isolated from cholera stool samples collected simultaneously from icddr,b Dhaka hospital for comparison.

Outcome measures/variables

This study will generate invaluable information on the nature of the vibrio phages, their seasonal dynamics, interrelationships, virulence, and disease transmission. The data generated would be important because the Bay of Bengal estuary is the historical reservoir for V. cholerae causing Asiatic cholera, and its specific phages.

Phages predate on V. cholerae and plays a role in shaping up of the epidemic clone. We designed this study to unveil the impact of phages on the Vibrio cholerae life cycle in Bangladesh.

The seasonality and dynamics of phages, and their interaction with Vibrio cholerae will aid prevention of cholera transmission.

Burden

Cholera, caused by V. cholerae, is a killer disease. In Bangladesh, cholera occurs endemically at defined seasons resulting significant morbidity and mortality each year. V. cholerae is a native flora of the estuarine aquatic environment. The bacterium existing in the environment is found mostly in a dormant, non-cultivable state; and can regain active state and flourish to initiate the seasonal epidemics of cholera. Although seasonal cholera is driven by natural climate factors, the disease takes the turn of epidemic through rapid transmission of infectious V. cholerae via fecal-oral mode as marginal people relies on contaminated surface water for drinking and other domestic purposes.

Knowledge gap

We want to understand V. cholerae growth response, particularly what triggers the bacterium to be active from dormant non-culturable state, and if locally available no-cost items such as ashes could kill the infectious bacterium shed in stool to decontaminate the environment; the aim is to develop a sustainable method to prevent cholera transmission.

Relevance

This study will generate knowledge on V. cholerae growth responses, and no-cost method of stool decontamination, and the aim is prevent cholera transmission.

Hypothesis

• Climatic and human factors contribute to active growth of V. cholerae responsible for seasonal cholera to prevent cholera transmission
• Wood ashes might provide a sustainable method of stool decontamination to prevent V. cholerae transmission

Objectives

• Study the environmental and human factors activating naturally occurring non-cuturable V. cholerae that initiates seasonal cholera
• Test efficacy of wood ashes in decontaminating V. cholerae shed in stools to reduce cholera transmission

Methods

Water samples will be collected from four Mathbaria sites, and temperature, turbidity, pH, salinity, total dissolved solids and conductivity of water monitored bi-weekly during March-May and September-November and monthly for the rest of the year. Toxigenic V. cholerae will be isolated (Alam et al. 2006a) and characterized in terms of virulence adaptive polymorphisms (VAPs) and molecular fingerprinting. Also, laboratory microcosms will be constructed with two toxigenic V. cholerae to test growth response of the bacterium, and the role of cyanobacteria (Islam et al., 1990a; Islam et al., 1990b) and bile will be monitored at different temperatures, pH, salinity, and conductivity. In this study, efficacy of decontamination of discarded diarrheal stools carrying V. cholerae would be monitored and compared with commercially available disinfectant such as bleaching powder.

Outcome measures/variables

Growth response of V. cholerae to different climate factors, and the role of cyanobacteria and bile in microcosms would be an outcome to measure. V. cholerae burden in cholera stool at different concentrations and time of treatment with wood-ashes would also be an outcome measure.

Vibrio cholerae often escapes culturing methods while in a dormant and non-culturable state in the aquatic environment, although they can become actively growing to cause seasonal epidemicsof cholera. We designed this study to unveil the climate and/or natural no-cost substaces that could drive the growth responses of the bacterium to be able to aid diseases prevention in endemic settings.

Vibrio cholerae is an aquatic bacterium which passes the interepidemic period in a dormant and non-culturable state. The well-defined climate or natural factors driving the growth responses of the bacterium could aid in diseases prevention in endemic settings.

Burden

Cholera is a deadly disease with approximately 3-5 million cases and over 1,00,000 deaths annually worldwide. Cholera is a seasonal disease caused by the bacterium V. cholerae which is autochthonous to the aquatic environment. Although it is well established that the disease transmits through water rapidly giving rise to large epidemics, factors contributing to the seasonality of cholera by activating the bacterium persisting in biofilms and in association with planktons in the environment and linkage between archived and newly disseminating 7PET sublineages, remain a longstanding question to answer.

Knowledge gap

Combined these data suggest that areas of high cholera incidence in Africa and during the 1990’s in Latin America, can be viewed as sinks for the epidemic cholera causing lineage 7PET and not the original source. Whilst data supporting this are substantive, we lack a detailed whole genome view of the environmental isolates of V. cholerae (O1, O139, and non-O1/non-O139) from Inland, coastal and estuarine environments of West Bengal and Northern regions of India and Bangladesh, the South Asian ‘hotspot’ of epidemic cholera.

Relevance

Unveiling the natural climatic factors that contribute to the seasonal epidemics of cholera would be of preventive implication. If we are to understand the drivers behind the emergence and spread of newly disseminating 7PET sublineages then we must focus attention on the Ganges Delta region, understanding how and where its unique ecology supports the emergence and spread of epidemic V. cholerae.

Hypothesis

The environmental Vibrio cholerae population in the Bay of Bengal supports the emergence of pandemic cholera

Objectives:

The specific objectives of this project are as follows:

• Generate a long term genomic view of environmental V. cholerae in Bangladesh from live archived samples to understand their evolutionary dynamics and their relationship to 7PET epidemic V. cholerae
• Link genome evolution of V. cholerae to environmental conditions and flux

Methods

Environmental surveillance will be conducted at six river sites of Dhaka, the capital of Bangladesh; five pond and one river sites of Mathbaria, coastal village of Bangladesh; and six river sites of Chhatak, a northern district of Bangladesh. Environmental water samples will be collected bi-weekly during seasonal epidemics of cholera i.e. during March-May and September-November at Dhaka and Mathbaria, September-November at Chhatak and monthly during the rest of the year. The samples will be monitored for environmental parameters such as temperature, turbidity, pH, salinity, total dissolved solids and conductivity. Samples will be transferred to icddr,b central Laboratory at Dhaka at ambient temperature for further analyses (Alam et al. 2006a). Toxigenic V. cholerae will be isolated from the water samples following standard culture methods, and characterized locally at icddr,b (Alam et al. 2006b, c) and also, shipped to Wellcome Sanger Institute, UK for whole genome sequencing.

Outcome measures/variables

Through the collaboration this proposal brings together expertise in high throughput genomics and world leading cholera environmental microbiology and public health in three countries. This will enable a much-needed multidisciplinary research programme to understand the emergence of 7PET. Expected outcomes are i) the publication of research findings in International journals ii) deposition of genome scale data sets in databases for future use iii) a comprehensive genomic understanding of how the 7PET lineage emerge from this region to cause outbreaks globally v) data that will inform cholera control strategies through the WHO Global Task Force for cholera control.

Genome sequencing data can reliably be used for source tracking and mode and route of transmission of a pathogen. The 7th pandemic El Tor is transmitted globally, but the sources is believed to be Asia. We designed this study to have a comprehensive genomic view to understand how the 7PET lineage emerges from this region and spread globally; aim is to control cholera.

A comprehensive genomic view will allow us to understand how the 7PET lineage emerges from this region to cause outbreaks globally; and to inform cholera control strategies through the WHO Global Task Force for cholera control.

Burden

Cholera is a deadly disease with approximately 3-5 million cases and over 1,00,000 deaths annually worldwide. Of the 1.3 billion people at risk worldwide, 66 million are in Bangladesh equating to approximately 40% of the Bangladeshi population. In addition, refugee movement bring increased risk from this disease. Bangladesh is one of the Least Developed Countries list of ODA recipients and together with India has the largest population at risk of Cholera. Rapid diagnosis and early detection of outbreaks are key aspects to fight cholera. Moreover, the indiscriminate use of wide-spectrum antibiotics creates the additional threat of antibacterial resistance (ABR) in V. cholerae population.

Knowledge gap

Microbiological testing is resource-intensive, and outbreak detection is mostly based on unreliable reports of cholera-like diarrhoea cases from local hospitals. Advances in diagnostics, treatment selection and outbreak tracking are much-needed for progressing towards eliminating cholera as a public health threat by 2030, a recently proclaimed objective by the WHO-backed Global Taskforce for Cholera Control.

Relevance

The aggregation of geo-localised clinical, environmental, and societal information collected for the development of the diagnostic and early prediction systems, and the additional data continuously collected during the deployment and operation of such systems, will constitute an invaluable databank shareable across follow-on and collaborative projects and eventually across countries.

Hypothesis

Significant changes in understanding transmission dynamics of antimicrobial resistant V. cholerae in Bangladesh by big data mining and machine learning with better local community decision making to improve diagnosis and treatment of cholera.

Objectives

The specific objectives of this project are as follows:

• Develop a portable, real-time diagnostics solution for cholera infection caused by antimicrobial resistant V. cholerae
• Develop a surveillance system to identify hot spots with higher likelihood of outbreak
• Development of a shareable databank

Methods

Samples will be collected from Dhaka Hospital, Mathbaria Thana Health Complex, Cox’s Bazar Hospital and Rohingya camp. Immediate after collection, samples will be subjected to RDT. If the sample is positive for either V. cholerae O1 or O139 then one aliquot will be stored at -80°C freezer at icddr,b for future use and another aliquot will be transferred to NSU, Bangladesh for further analysis (Alam et al. 2006a). Water samples will also be collected from 6 sites each, for Dhaka city, Mathbaria, and Cox’s Bazar. Toxigenic V. cholerae will be isolated from stool and water samples following standard culture methods, and characterized for antibiotic resistance (Alam et al. 2006b, c). Both types of samples will be subjected to Nanopore genome sequencing.

Outcome measures/variables

Through the collaboration this proposal brings expertise together to work on public health. This will enable a much-needed multidisciplinary research programme to diagnose cholera using Nanopore genome sequencing, treatment selection, epidemiological forecasting for infection and antibacterial resistance, ultimately contributing to improving health, welfare and economic growth of Bangladesh.

Data mining and machine learning appear to offer better resolution for improving accuracy of diagnosis of a pathogen. The portable real-time nannopore sequencing device could provide diagnostic solution at field level. We designed this big data mining and machine learning study to improve diagnostics and treatment selection for cholera infection caused by antimicrobial resistant V. cholerae.

A portable real-time diagnostics solution for cholera infection caused by antimicrobial resistant V. cholerae with big data mining and machine learning to improve diagnostics and treatment selection.

Background

Cholera is a rapidly dehydrating diarrheal illness and remains a global threat to public health. Recently it has been estimated that there are approximately 2.8 million cholera cases and 91,500 cholera deaths in cholera-endemic countries. Till date, no medication exists which can quickly curtail cholera diarrhea.

Knowledge gap

Currently, there have not been studies to understand whether vasoactive intestinal polypeptide (VIP) is a mediator in the pathogenesis of cholera.

Relevance

If VIP is a mediator for cholera diarrhoea, VIP antagonists/blockers could significantly curtail cholera diarrhea. Hopefully this might reduce cholera related morbidity & mortality in endemic countries.

Objectives

To determine VIP levels in cholera ricewater stool and in patients’ plasma obtained simultaneously, both before and after correction of severe dehydration using standard intravenous rehydration and maintenance therapy. Thus to confirm a role of VIP in cholera pathophysiology.

Methods

This would be a descriptive study, patients of either sex, aged 18-64 years attending the Dhaka Hospital of icddr,b with severe dehydration due to cholera will comprise the study population. Rectal catheter stool & venous blood specimen will be obtained just before initiation of IV rehydration therapy, after post rehydration, 24 hours after post rehydration & before discharge.

Outcome measures/variables

Primary outcome measure will be stool & plasma VIP level before & after correction of severe dehydration
Secondary outcome measures will be time to cessation of diarrhoea, the total volume of stool output (ml/kg/hr), the total volume of IVF received, and the total volume of ORS received, development of any severe complications, as decided by treating physician.

Cholera is diarrheal illness and can cause severe dehydration rapidly. Cholera remains a global threat to public health. Recently it has been estimated that there are approximately 2.8 million cholera cases and 91,500 cholera deaths in cholera-endemic countries. Till date, no medication exists which can quickly curtail cholera diarrhea. Currently, there have not been studies to understand whether Vasoactive intestinal peptide (VIP) is a mediator in the pathogenesis of cholera. If VIP is a mediator for cholera diarrhoea, VIP antagonists/blockers could significantly curtail cholera diarrhea. Hopefully this might reduce cholera related morbidity & mortality in endemic countries.

If VIP is a mediator for cholera diarrhoea, VIP antagonists/blockers could significantly curtail cholera diarrhea. Hopefully this might reduce cholera related morbidity & mortality in endemic countries.

Background

Cholera is an acute dehydrating diarrheal illness caused by Vibrio cholerae infection, accounting for more than 3 million cases and 100,000 deaths a year globally. In endemic countries, young children bear a large burden of disease.

Knowledge gap

Despite this, currently available cholera vaccines achieve a lower efficacy and shorter duration of protection in young children than in adults for reasons that are poorly understood, while such differences in protection are not evident following natural infection. We have recently shown, in a cohort of Bangladeshi children, that younger children given oral cholera vaccine mount lower V. cholerae polysaccharide-specific antibody responses compared to older children and adults.

Relevance

Mucosal-associated invariant T (MAIT) cells are recently described innate-like T cells, representing 1-10% of circulating T cells, and found in abundance in the intestinal mucosa, mesenteric lymph nodes, and liver. MAIT cells are predominantly CD8+ and restricted by the non-polymorphic MHC-related protein 1 (MR1), and activated by pathogen-derived vitamin B metabolites. Despite their innate-like features, recent studies have found that MAIT cells have surprising heterogeneity in their TCR repertoire and can discriminate between pathogen-derived ligands in a clonotype-dependent manner.

In collaboration with scientists at the University of Utah, we have examined both peripheral and duodenal MAIT cells in humans with severe cholera. We found that MAIT cells are activated in both the peripheral and mucosal compartments during cholera infection, and that they are associated with higher class-switched V. cholerae polysaccharide-specific antibody responses. Additionally, in a set of in vitro studies using primary MAIT cells and MAIT clones expanded from healthy individuals, we have shown that MAIT cells promote B cell differentiation and antibody production. We have also used transcriptomic analysis to demonstrate that activated MAIT cells have increased expression of CD40L and APRIL, factors known to play a role in B cell activation. Thus, we hypothesize that in mucosal infection and vaccination, MAIT cells play an important role in bridging innate and adaptive immune responses, including a possible effect on polysaccharide-specific responses.

Building on these data, and taking advantage of our longstanding collaboration with scientists at the University of Utah and Harvard Medical School, we propose to use V. cholerae as a prototypical human enteric pathogen to understand the adaptive capacity and B cell impact of MAIT cells during enteric infection and vaccination.

Hypothesis

We will test the hypothesis that a subset of MAIT cells, when activated following infection or vaccination, undergo clonal expansion and provide help to B cells through MR1-dependent and -independent interactions to enhance polysaccharide-specific antibody production.

Objectives

The objective of this study is:

• To characterize clonal expansions of MAIT cells during human cholera infection and vaccination;
• To determine the mechanisms through which MAIT cells affect B cell maturation.

Methods

Isolation of PBMCs from blood by density gradient centrifugation from younger and older children vaccinees and infected younger children and clonal expansion of single sorted MAIT cells.

Outcome measures/variables

Generation of clones from the vaccinees and infected persons with Cholera.

Currently available cholera vaccines achieve a lower efficacy and shorter duration of protection in young children than in adults for reasons that are poorly understood, while such differences in protection are not evident following natural infection. We have recently shown, in a cohort of Bangladeshi children, that younger children given oral cholera vaccine mount lower V. cholerae polysaccharide-specific antibody responses compared to older children and adults.

The objective of this study is:

• To characterize clonal expansions of MAIT cells during human cholera infection and vaccination;
• To determine the mechanisms through which MAIT cells affect B cell maturation.

Generation of MAIT cell clones from the vaccinees and infected persons with cholera may help to understand and use those as therapeutics for control of cholera.

Background

Cholera is endemic in Bangladesh. The current method for testing samples requires three days and notification of results can take even longer. We hope to evaluate a device that could lessen that time required.

Knowledge gap

We hypothesize that there will be 90% accuracy of the device compared to the gold standard in terms of correct identification and we wish to test that.

Relevance

In order to implement the device to identify dangerous water samples, the device must first be proven to be accurate at a satisfactory level. Therefore the hypothesis will be tested and conclusions drawn to determine the accuracy.

Hypothesis

The accuracy of the device will be 90% compared to the gold standard.

Objectives

Determine sensitivity and specificity of device in field. Discover and address any complications not found in lab that arise in field use. Draw conclusions about the validity of device

Methods

The OmniVis diagnosis process begins with a primer chip. The chip is a one-time-use disposable test kit that contains a freeze-dried biological assay specific for the ctxA gene of Vibrio cholerae. The assay includes six primers for the LAMP technique: F3, B3, FIP, BIP, LF, and LB. The shelf life of the chip with the freeze-dried primer is unknown; it has been proven viable for four months without the need for temperature or humidity regulation when stored with a desiccant. The transportation of the necessary equipment including these primers will be handled by OmniVis via shipment to Bangladesh or direct delivery by OmniVis staff. The chip has a reservoir that will fill when the chip is dipped into the water. The chip will be dipped into the water where it collects between 15 and 25 gl of water. The chip will be dried with a paper towel after which the app analysis will start. All waste products will be transported in biohazard bags and autoclaved before disposal.

Once the water sample is in the chip and the chip is dried, the app is started. The interface shows the user where to insert the chip into the heater. Once the chip is in, the heater works for thirty minutes while a flame moves up the screen to show the progress. During this phase, the LAMP technique is carried out in the housing. Samples containing the ctxA gene will undergo DNA polymerization resulting in the amplification of the strands. This process causes the toxic sample to have a higher viscosity from the saturation of DNA. Samples without the targeted gene will not undergo a significant change in viscosity as no DNA will amplify. The viscosity of the strands of non-amplified samples are significantly different from the polymerized strands — providing the basis for the in-app analytical algorithms measuring the Brownian motion. Once the heating portion is complete, the app prompts for the removal of the chip and the insertion into the camera slot where the microscope lens is used to analyze the sample. There the Brownian motion of the sample is measured via in-app algorithms using the iPhone camera and microscope lens in the apparatus. This analysis can take up to a few minutes after which the app displays the result showing either a cholera-contaminated sample or not. Our application will show us the diffusion coefficient measured by the camera in terms of m/s^2 so that analysis can be carried out on the data. GPS location will be recorded at the time of completion and the diffusion coefficient and location will be stored on the phone. The phone will transfer the data to a cloud server where the data can be accessed.

The previously established conventional sample enrichment technique or “gold standard” of cholera detection will be run in addition to the cellular diagnostic device. The gold standard for cholera detection is a time-intensive lab test to identify the presence of cholera in a sample. Alam’s 2015 study outlined the laboratory test. Water samples of 500 ml were collected from a site and incubated in 2X alk.

Cholera is endemic in Bangladesh. Community water sources contaminated with the bacteria place communities at risk of cholera infection and death.The current method for testing samples requires three days and notification of results can take even longer. We hope to evaluate a device that could lessen that time required.

The rationale behind studying the OmniVis device is the potential to reduce this test-time and reporting to communities. We hypothesize that it will take approximately 30 minutes to complete a water test and determine if the sample is contaminated with cholera. In order to implement the device to identify dangerous water samples contaminated with the cholera germs, the device must first be proven to be accurate at a satisfactory level. The objective of the project is to determine sensitivity and specificity of device in field; Discover and address any complications not found in lab that arise in field use; Draw conclusions about the validity of device.

The research project is designed to compare capability of the Omnivis Technologies rapid cholera detection device and conventional cholera detection method from water by comparing water sample analysis data of both. Based on the comparison, conclusions will be drawn to determine the accuracy.

This research project will generate evidence/data which will be used to improve the accuracy and efficacy of the OmniVis Technologies rapid cholera detection device. Potential use of the OmniVis device to detect dangerous water sample (contaminated with Vibrio cholerae) instantly from water body will lead to proper management, decision-making and control of the cholera epidemic at the initial stage by the government in future.

The prevention of cholera has become a high priority in the global community. Immunization with OCV is the most effective means of preventing cholera infection and it’s consequences. The World Health Organization (WHO) has warned of a growing risk of a cholera epidemic at the Rohingya camps in Bangladesh where people are sheltered in dire conditions. The camps do not have safe drinking water and lacked sufficient sanitation and hygiene; filthy water and faeces flowed openly through the camps. Risk of waterborne diseases is very high, especially there is increasing the risk of cholera in these camp. Over a million Forcibly Displaced Myanmar Nationals (FDMNs) have been residing in different camps of Ukhia and Teknaf, the two upazilla of Cox’s Bazar. Around the camps, the Bangladeshi host population are also living in close proximity to the FDMNs. The risk of cholera and other diarrhoeal diseases are similarly present for the host community and the fragile population. Moreover, according to WHO, a total number of 782 cases with 11 deaths have been reported in 2016 from Myanmer when the case fatality rate was 1.4%. Interventions like vaccination are being scaled-up as the situation remains critical and challenging. In addition, an impact evaluation of the effectiveness of the mass OCV campaigns carried out between October 2017 to December 2018 is ongoing. This has been carried out in 13 sites in Teknaf (n=2) and Ukhia (n=11). But information related to cholera burden among the FDMNs and host community is necessary to detect epidemics and outbreaks which will leverage cholera containment through vaccination and WASH activities. The objective of this study to carry out cholera surveillance at selected health facilities in Ukhiya and Teknaf Upazila, Cox’sbazar to gather information regarding cholera burden among fragile population (FDMN) and host community.

The icddr,b and IVI have collaborated on multiple research projects addressing the epidemiology of vaccines for cholera. This is in addition to each institution`s individual work on cholera and typhoid fever. To date, papers with significant global health impact been published on these studies, yet, the papers are relatively few in number in relation to the size and richness of the data available from the studies. Computerized datasets from these projects have been cleaned, archived, and documented, and are available for analyses. These datasets thus constitute an important resource for further analyses and publications addressing critical issues related to control of cholera and typhoid by both vaccine and non-vaccine (WASH) measures.

The purpose of this proposal is to:

• To answer scientific questions and publish manuscripts in the international scientific journals using existing computerized and curetted datasets for analyses of the epidemiology of cholera and typhoid, as well as the effectiveness of vaccine and WASH control measures for the control of these disease.
• To form a working group consisting of both senior and junior scientists from each institution, together with selected experts from outside the institutions, to exploit the untapped existing computerized and curetted datasets.

We will achieve the objectives by forming working groups consisting of senior and junior scientists together with a steering committee composed of selected experts from outside the institutions, to analyze the existing datasets and to submit manuscripts based on these analyses for publication in the international scientific literature. We will also present the findings at international scientific meetings and forums. In addition, after completion of the proposal in the 2 year period targeted for the study, the results will be shared with Institute for Health Metrics and Evaluation (IHME), as necessary, to strengthen the cholera and typhoid fever disease burden data.

The vaccine effectiveness will be measured by comparing the ratio of odds of vaccination in the cholera positive patients and odds of vaccination in the cholera negative patients.

In 2018, the World Health Organization (WHO) Global Task Force on Cholera Control (GTFCC) declared an objective to reduce global cholera mortality by 90% and eliminate cholera in 20 priority countries by 2030. Despite years of cholera research, however, the burden and geographic variability of cholera across India is poorly understood due to underreporting, limited laboratory capacity, inconsistent case definitions, and apprehensions of negative impacts on travel, trade and commerce.

To address the issue, we propose to estimate incidence of V. cholerae O1 infections across 5 regions of India using seroepidemiological methods along with triangulation of data on cholera from available multiple sources (a) published literature and grey literature archives (b) program data like Integrated Disease Surveillance Program (IDSP), Field Epidemiology Training Program (FETP) reports, National Health Profile (NHP) maintained by Central Bureau of Health Intelligence (CBHI) and data on Swacch Bharat initiated sanitation drive (c) information from annual reports and (d) serological testing (vibriocidal) for cholera markers on stored samples collected during Dengue National serosurvey. Results from this study will generate robust estimates on risk-prone areas vulnerable to cholera outbreaks in India. Additionally, this will inform the selection of sentinel surveillance sites for the monitoring of culture-positive cholera cases. Given the genetic similarity of V. cholerae strains from other geographical regions, this study will have a profound impact on national and global levels.

This study will identify incidence of cholera in 5 regions of India through measuring the antibody levels in serum. A hotspot mapping of different regions and states in India will be done for Cholera by combining estimates of antibody proportion and magnitude of reported cholera in different types of published literature.

Results from this study will generate robust estimates on risk-prone areas vulnerable to cholera outbreaks in India. Additionally, this will inform the selection of sentinel surveillance sites for the monitoring of culture-positive cholera cases. Given the genetic similarity of V. cholerae strains from other geographical regions, this study will have a profound impact on national and global levels

Cholera is an acute watery diarrhoeal disease that can lead to severe dehydration and death in less than 16 hours. It is an important public health problem in Asia, Africa and Latin America. Globally 1.3-4 million cases and 21,000-143,000 deaths occur annually due to cholera1. Accurate diagnosis of cholera early in an epidemic is critical to reduce morbidity and mortality. Rapid diagnostic tests (RDTs) have the potential to provide immediate objective findings early in outbreaks in settings that lack conventional microbiology laboratories. Several lateral flow immunoassay-based RDTs are commercially available and target V. cholerae O1 and/or O139 specific antigens. However, the RDT performance metrics are unpredictable for unknown reasons which has resulted in limited adoption. We are specifically interested in the widely used RDT sold under the name of Crystal VC (Span Diagnostics, India) that was developed by the Institute Pasteur.

While limitations with current RDTs may include production and operator problems, there are multiple biologic reasons why the RDT may fail when deployed in field settings. One explanation is that the concentration of Vibrio cholerae may fall below the limit of detection when the bacteria are preyed upon by viruses called lytic vibriophages. This predation is dynamic to the ratio of predator / prey. We have shown that vibriophage (ICP1) negatively impacts the RDT (see preliminary data section).

Our primary research question is if the incorporation of antibodies that detect both V. cholerae and lytic vibriophage into a Rapid Diagnostic Test (RDT) will address limitations in the current RDTs used when cholera patients harbor lytic vibriophage. This novel RDT may represent a model for diagnostic tool development for enteric and nonenteric infectious diseases. To develop this RDT and answer this question we propose the following specific aims:

Aim 1

Identify lytic vibriophage structural and non-structural proteins that are antigenically unique in diarrheal stool. We hypothesize that lytic vibriophage express structural and non-structural proteins that are antigenically unique. These proteins can be used to generate a monoclonal antibodies (mAb) that can then be incorporated into an improved RDT. We will take two approaches to identify unique immunogenic vibriophage proteins with specific focus on ICP1 because it has been shown to be most common in multiple locations.
1.1 Reverse vaccinology by genomic analysis, cloning, expression, and testing immunogenicity
1.2 Proteomic analysis of immunogenic proteins separated by 2-D gel electrophoresis and MALDI-TOF

Aim 2

Produce monoclonal antibodies (mAbs) against unique lytic vibriophage protein. The vibriophage proteins identified in Aim 1 will be used to raise mAbs using both hybridoma and in vivo ascites techniques.
2.1 Immunize animal model with vibriophage proteins and screen for antibody producing hybridoma clones
2.2 Propagate selected hybridoma cells in vivo using ascites method for mAb production and affinity purification

Aim 3

Produce, test and select candidate RDTs by highest performance metrics. The monoclonal antibodies produced by hybridoma technology will be used to develop an immune-assay based lateral flow test; this test will include the existing (or equivalent) commercial mAb for V. cholerae O1 LPS. Several RDTs with different mAb candidates will be evaluated.
3.1 Conjugate colloidal gold to mAb and assemble the lateral flow strip
3.2 Evaluate the performance of the RDTs against commercially available RDTs with a clinical sample library

It is likely that rapid diagnostic tests (RDTs) for cholera intermittently fail because lytic vibriophage destroy the Vibrio cholerae target. In this proposal, we are adding an antibody to the lytic vibriophage (ICP1) to the RDT. The goal is that detection of the vibriophage can serve as a proxy for Vibrio cholerae, and therefore, increase sensitivity of the RDT when vibriophage are present.

This revised RDT will address sensitivity concerns and intermittent performance of current RDTs when lytic vibriophage are present. This new RDT will not address limitations when antibiotics are present, and therefore patient reports on antibiotic consumption need to be consider when evaluating RDT results, even with the new RDT.

For over ten years, we have sought how best to develop decision-support tools for clinicians treating diarrhoeal disease. This is important because of a need to rapidly train large numbers of providers during cholera outbreaks, rapidly re-educate when guidelines change, address inappropriate antibiotic use, and allow for differences in epidemiology by season and place. We have built tools in both paper and digital formats, and evaluated their impact in clinical trials. Now, we are collaboratively building digital tools that depend on models developed through machine learning. In a large international collaboration, we have built and evaluated improved algorithms to assess dehydration for children and adults (project led by A. Levine at Brown University) and provide a probability that a patient has only a viral disease based on real-time weather, clinical and epidemiologic data (project led by D. Leung at Utah University). In addition to helping to improve cholera response, these tools represent a significant shift in how clinical decision-support might be in 10 years.

The impact of this research is to first improve rehydration and antibiotic guideline adherence. Secondly, the impact is to make possible dynamic decision-support that is responsive to where and when the patient is being treated.

The cholera burden is concentrated in endemic settings with inadequate water, sanitation and hygiene access. There is limited rigorous evidence for the impact of improved water supply on endemic cholera transmission in low-income urban settings. We propose a pragmatic health impact evaluation of a large-scale water supply intervention in Uvira (South Kivu, Democratic Republic of the Congo), a cholera transmission hotspot. A stepped-wedge cluster randomised trial (SW-CRT) was designed to evaluate the impact of a large-scale drinking water supply intervention on cholera incidence among the 280,000 inhabitants of Uvira. The city was divided into 16 clusters, where new community and household taps will be installed following a randomised sequence over a transition period of up to 8 weeks in each cluster. The primary trial outcomes are the monthly incidence of “confirmed” cholera cases (patients testing positive by rapid detection kit) and of “suspected” cholera cases (patients admitted to the cholera treatment centre). Concurrent process and economic evaluations will provide further information on the context, costs and efficiency of the intervention. Overall, this research has the potential to provide robust evidence to support more effective cholera prevention in challenging, high-burden settings. This trial is registered on clinicaltrials.gov (NCT02928341).

The Uvira research provides a unique opportunity to inform future investments in water supply infrastructure improvements and cholera prevention strategies in endemic transmission hotspots.

In this project, we are working to complete a systematic review (stratifying cholera WASH evidence by context), and to convene a working group to inform WASH components of National Cholera Control Plan development.

The project aims to inform National Cholera Control Plan Development.

In this project, we:

• analyzed monitoring data collected by partners in Nigeria during cholera;
• completed key informant interviews with people collecting and inputing data;
• suggested improvements to the monitoring tools and Kobo platform.

The project aimed to assist in cholera monitoring in Nigeria.

In this project we:

• conducted laboratory work to determine the efficacy of surface disinfection and bucket chlorination at removing V. cholerae from surfaces;
• conducted nine field evaluations in humanitarian response on bucket chlorination, household spraying, and household disinfection kit interventions;
• are developing policy on surface disinfection and bucket chlorination to prevent the spread of cholera.

The project provided key information on efficacy, effectiveness, and guidance for the interventions of household disinfection and bucket chlorination.

In this project we:

• conducted three mixed-methods, multi-country evaluations of water trucking in humanitarian responses;
• developed methods, and conducted large- and small-scale laboratory studies on how to clean jerricans, containers, and taps (water storage containers) to prevent biofilm development or remove biofilms;
• developed a protocol to determine the most appropriate chlorine tablet for a particular emergency context.

The project provided key information on efficacy, effectiveness, and guidance for bucket chlorination, water trucking, jerrican cleaning, and chlorine tablet selection.

In this project, we evaluated a program where Red Crescent volunteers staffed ORPs locally in conflict-affected areas. It was found volunteers could effectively staff the ORPs, provide ORS to minor cases, and refer moderate/sever cases. However, the mobile phone based monitoring system was not effectively established.

It is recommended to continue using volunteers to staff ORP.

Cholera continues to cause significant morbidity and mortality throughout the developing world. The primary objective of the original proposal was to test the hypothesis that environmental factors involving surface waters were responsible for the observed periodicity and pandemic nature of cholera. Data collected from our pervious study (2003 -2007) strongly suggest, that environmental factors are predictive of cholera outbreaks. Work will now focus on the positive associations that were found, and comparing the V. cholerae strains isolated from the environment and those from patients. With our successes to date, we will continue clinical and environmental surveillance in association with ICDDR,B, the University of Maryland Biotechnology Institute and School of Medicine, and Emory University and Johns Hopkins University, Bloomberg School of public Health, USA. Clinical and environmental surveillance will continue at Mathbaria one of the original sites near the Sundarbans, area of mangrove swamps close to the Bay of Bengal. We have replaced Bakerganj by Chhatak, which is situated in the north eastern part of the country. These two widely separated geographical sites have documented different seasonal cholera outbreaks. We will continue to use assays which will focus on 1) identifying V. cholerae (both culturable and viable but not culturable cells (VBNC) in surface waters, using both standard techniques and colony blots with non-radioactive DNA probes (for V. cholerae species, O1, O139, ctx, and tcpA) DNA extraction, and PCR, 2) assessing the relationship between clinical and environmental isolates by genotyping (using AFLP, ERIC-PCR, and MLST) and 3) identifying and enumerating V. cholerae attached to plankton using direct fluorescent antibody techniques, and fluorescent in-situ hybridization assays. Using improved assays, developed during the course of current study we will determine genetic associations between clinical and environmental isolates which will enable us to establish key epidemiological relationships that have been difficult to document at the genomic level. We will develop refined model of cholera transmission by including factors recognized from our previous study, incorporating the new variables that prove to be correlated with cholera case, but not yet included in our predictive model.

Using these data we will further refine our model of cholera transmission which will be useful in predicting outbreaks of cholera, thereby facilitate early mobilization of preventive and treatment measures

Burden

Diarrhea is the second most leading causes of deaths in children under 5 years of age globally, with an estimated 800,000 deaths annually. On an average, a child in Bangladesh suffers from 3-5 episodes of diarrhea per year. Children suffering from frequent and recurrent diarrhea suffer from food wasting, and the ultimate result is severe malnutrition and growth stunting. Once stunted, its effects typically become permanent, and children may never regain the height lost as a result of stunting. Previous studies have identified lack of caregiver hand washing with soap and treatment of household drinking water, poor water storage practices, and lack of caregivers knowledge about diarrhea prevention as important risk factors for diarrheal disease in paediatric populations. Water, sanitation, and hygiene (WASH) interventions promoting household chlorination of drinking water and hand washing with soap have the potential to reduce diarrheal disease incidence in children less than five years of age an estimated 30 to 40%. Furthermore, Community Based WASH interventions are expensive and often difficult to implement in an urban context in low resource settings. Our team has recently developed a Hospital Based WASH intervention which is entitled CHoBI7 (Cholera Hospital-Based Intervention for 7 days). The CHoBI7 intervention was initially designed to reduce cholera infection among family members of hospitalized cholera cases during the one week high risk period after the case presents at the hospital. This low cost Hospital Based WASH intervention resulted in a significant reduction in the incidence of symptomatic cholera, and a 47% percent reduction in the incidence of cholera infection among household members of hospitalized cholera cases. Furthermore, we observed sustained uptake of the promoted hand washing with soap and water treatment behaviours among intervention households 6 to 12 months after the intervention was delivered.

Knowledge gap

Despite successful intervention in our just concluded hospital based study we still do not understand if all the procedures involved can be integrated into the services provided for hospitalized diarrhea patients at health facilities of Bangladesh and the promoted hand washing with soap and water and water treatment behaviour would be a long lasting practice in the community.

Hypothesis

Based on what we have learned from our just concluded Hospital Based WASH intervention study entitled “Cholera Hospital-Based Intervention for 7 day” (CHoBI7), we hypothesize that developing and evaluating scalable approaches might help this innovative and low cost CHoBI7 intervention to be integrated into the services provided for hospitalized diarrhea patients at the health facilities of Bangladesh. We also hypothesize that evaluating the ability of the CHoBI7 intervention, which could lead to a sustained uptake of the promoted hand washing with soap and water treatment behaviours might reduce the burden of diarrheal diseases over time.

Objective 1

To Develop scalable approaches to integrate the CHoBI7 intervention in urban health facilities through formative research and engagement of key stakeholders.

Objective 3

Investigate the effectiveness of the developed scalable approaches for program delivery of CHoBI7 in terms of: (1) reductions in diarrheal disease prevalence during the 12 months period after the index diarrhea patient in the health facility receives the intervention; and (2) sustained high uptake of hand washing with soap and water treatment practices at 1 week, 1 month, 3 months, 6 months, 9 months, and 12 months post intervention.

Objective 3

Calculate the cost effectiveness of upscaling the CHoBI7 intervention in terms of cost per Disability Adjusted Life Year (DALY) averted and case and death averted for cholera and moderate to severe diarrhea episodes.

Objective 4

Investigate the feasibility of implementing the proposed low cost approaches for program delivery of CHoBI7 as part of the National Emerging and Re-emerging Diseases Program through identification of potential barriers to successful implementation, and engagement with key government stakeholders.

Objective 5

Disseminate the findings of CHoBI7 intervention implementation and evaluation activities and our recent CHoBI7 efficacy trial at the household, health facility, and national and local government levels through the creation of a website, policy planning workshops with government leaders, development of policy briefs, publishing finding in peer reviewed scientific journals, and presentations at international scientific meetings.

Methods

Diarrheal patients admitted to icddr,b Dhaka Hospital or Mugda General Hospital would be screened and enrolled according to inclusion criteria. Diarrhea patients will be recruited after they received ORS or intravenous rehydration. Household members would be recruited those accompanying the diarrhea patient to the hospital and reside in the home of the enrolled diarrhea patient. Written informed consent would be taken from the patients and their HHC before enrolment. A baseline questionnaire will then be administered to each enrolled diarrhea patient and enrolled accompanying household members (adult and child), stool sample will be collected, and anthropometric measurements will be performed. After the baseline questionnaire is administered to the index diarrhea patient and accompanying household members, they will then be randomized to their respective study arm (Control Arm/Health Facility Based Dissemination Arm / Health Facility Based Dissemination and Home Visits Arm) based on the day they arrive to the hospital. The first arm will receive the standard message given to hospitalized diarrhea patients in health facilities in Bangladesh on the use of oral rehydration solution (ORS) (Control Arm). The second arm will receive the standard message plus Health Facility Based Dissemination of CHoBI 7 (Health Facility Based Dissemination-Only Arm) and bi-weekly (every two weeks) follow-up phone calls or text messaging. The third arm will receive the standard message plus Health Facility Based Dissemination of CHoBI 7 plus two home visits (Health Facility Based Dissemination and Home Visits Arm) and biweekly follow-up phone calls or text messaging. These Randomized Control Trial activities would be 12 Months in duration in each enrolled household. Stool samples would be collected from the HHC on different time period, household drinking water would also be collected and direct observation (5 hr long) would also be performed.

Outcome measures/variables

Develop low cost effective strategies for delivering CHoBI7 in urban health facilities which can be integrated into the National Emerging and Re-emerging Diseases Program.

To prevent cholera epidemics and empower local public health service for sustainable cholera and other vaccine-preventable disease surveillance and control.The MOCA project was conducted in Cuamba Municipality District where cholera is found to be endemic and period outbreaks occur including the recent cholera epidemic in 2015.

Strengthened local capacity for cholera/diarrheal surveillance and laboratory diagnosis.

Prevention of cholera infection in vulnerable populations in Mozambique. Generation of data on the occurrence of cholera and other vaccine-preventable non-cholera diarrheal infections. Capacity-building of African scientists in the field of public health research collaborations particularly on diarrheal disease and cholera surveillance activities.

Every year cholera affects 1.3 to 4.0 million people worldwide with a particularly high presence in Africa. Based on recent studies, effective targeting interventions in hotspots could eliminate up to 50% of cases in Sub-Saharan Africa (1). Those interventions include Water, Sanitation and Hygiene (WASH) programs whose influence on cholera control, up to present, has been poorly quantified. Considering the limited number of studies on Community-Led Total Sanitation (CLTS) and water coverages related to cholera control, the aim of our work is to determine whether these interventions in cholera hotspots (geographic areas vulnerable to disease transmission) have significant impact on cholera transmission.

In this study, we consider data collected on 125 villages of the Madarounfa district (Niger) during the 2018 cholera outbreak. Using a hurdle model, our findings show that full access to improved sanitation significantly decreases the likelihood of cholera by 91% (P<0.0001) compared to villages no access to sanitation at all. Considering only the villages affected by cholera in the studied area, cholera cases decrease by a factor of 4.3 in those villages where there is partial access to at least quality water sources, while full access to improved water sources decrease the cholera cases by a factor of 6.3 when compared to villages without access to water (P<0.001).

In addition, villages without access to safe water and sanitation are 6.7 times (P<0.0001) more likely to get cholera. Alternatively, villages with full sanitation and water coverage are 9.1 (P < 0.0001) less likely to get cholera.

The findings of our study suggest that significant access to improved water and sanitation at the village level offer a strong barrier against cholera transmission. However, it requires full CLTS coverage of the village to observe strong impact on cholera as partial access only has a limited impact.

Influence on needs for WASH projects in hotspots in prevention of cholera.

Knowledge gap

To meet the ambitious goals set by the WHO of reducing cholera as a public health threat by 2030 and reduce cholera in the hyper endemic setting of Bangladesh, improving our methods for counting cholera cases and infections is critical for control planning. At present, most cholera burden estimates are derived from passive clinical based surveillance, which only captures a portion of true cases and infections due to barriers to healthcare seeking. While we have recently developed methods to estimate V. cholerae infection incidence at the population-level, some fundamental questions still remain on how to interpret this data in relation to clinical incidence. Furthermore, we know little about how the COVID-19 pandemic has affected healthcare seeking for cholera or what the seroprevalence of SARS-CoV-2 is in the population.

Relevance

Results from this study will improve our knowledge of cholera incidence in Bangladesh to aid the distribution of interventions like the oral cholera vaccine. Refining our methods for estimating cholera burden will additionally improve how we estimate cholera burden in other countries and estimate future vaccine demand. This study will also result in the estimation of the seroprevalence of SARS-CoV-2 infection in the study region in Bangladesh which will help inform the implementation of interventions like vaccination and improve our understanding of how the COVID-19 pandemic has disrupted healthcare seeking behaviors.

Objectives

The primary objective of this study is to improve and refine our methods for estimating correlates of cholera burden from cross-sectional serosurveys though enhanced clinical surveillance of cholera and serial serosurveys. A secondary objective of this study is to better understand the maturity of the SARS-COV-2 epidemic in this population by measuring the prevalence of SARS-COV-2 antibodies in the population and estimating key individual-, household- and community-level risk factors for infection.

Methods

The current national cholera surveillance program will be enhanced by recording and testing all individuals seeking care for suspected cholera, inpatient or outpatient, at the Bangladesh Institute of Tropical Infectious Diseases (BITID) and the Sitakunda Upazila Health Complex (UHC), for cholera. A study staff will be present at each health centre to monitor all points of triage and search for suspected cholera cases. In the second portion of the study we will enroll randomly selected households and follow ~1,632 individuals longitudinally across three time points to capture the low and high season of cholera. At each time point, participants will be administered a questionnaire regarding healthcare seeking and water and sanitation related behaviors and blood will be collected to measure seroincidence.

Outcome measures/variables

The questionnaire and blood collection will be conducted 3 times at each household selected for the cholera outcome. This will help to capture changes over the course of the typical high season for cholera at the study site while allowing for us to capture detailed surveillance data for the 6-month period before the initial survey. Our primary study outcome is the change in seroincidence between the first and third serosurvey. Estimation of the prevalence of anti-SARS-CoV-2 antibodies among individuals in the first serosurvey will give us good precision around plausible estimates of seroprevalence consistent with recent findings in Bangladesh.

In this study in Sitakunda, Bangladesh, we are trying to understand how to use antibody levels in people’s blood collected at a single point in time in a survey to estimate the rate of infections with Vibrio cholerae O1. Given that a large fraction of infections lead to mild disease or are asymptomatic, we are also studying how to translate infection rates to burden of disease.

This study will help us understand how seroepidemiology can be used to track changes in cholera over time complementing clinical cholera surveillance efforts

The objective of this study is to test the safety and immunogenicity of HaitiV – a novel live-attenuated cholera vaccine. Pre-clinical data suggest that HaitiV can provide rapid (within a day), single-dose, long-lived protection from cholera. The key goals of the study are 1) creation of a GMP lot of HaitiV for use in human studies and development and approval of an investigator sponsored Investigational New Drug application to conduct a first-inhuman Phase I trial of HaitiV; 2) determination of the maximum tolerated dose and safety profile of HaitiV; and 3) identification of the most immunogenic HaitiV dose. These studies will provide the pivotal data required for future development of this vaccine, including human challenge studies and field trials in cholera endemic regions.

Cholera remains an important challenge to global public health. Killed cholera vaccines have shown promise as tools for cholera control, but these vaccines have limitations, including minimal activity in children and delay in eliciting protection. In contrast to killed cholera vaccines, HaitiV, our novel highly engineered live-attenuated cholera vaccine, leverages the unusual capacity of the cholera pathogen to replicate in and colonize the human small intestine. Our pre-clinical studies in animal models have shown that administration of this live vaccine confers rapid protection to animals prior to engendering protective immune responses to a range of Vibrio cholerae antigens. Such rapid protection could have major impact on reactive cholera vaccine campaigns, curtailing epidemic spread. The vaccine also has great promise to provide single-dose long-lived protection in children as well as adults. Thus, completion of the proposed first-in-human trial of HaitiV could propel the development of a transformative new tool for global cholera control.

This study will yield critical data about a new agent for cholera control.

Prospective cohort study

Household contacts of cholera cases are at a greater risk of Vibrio cholerae infection than the general population. There is currently no agreed standard of care for household contacts, despite their high risk of infection, in cholera response strategies such as case-area targeted interventions (CATI). In 2018, hygiene kit distribution and health promotion was recommended by Médecins Sans Frontières for admitted patients and accompanying household members upon admission to the health care facilities, as part of an overall response to a cholera outbreak in the Democratic Republic of Congo (DRC).

To investigate the effectiveness of the intervention and risk factors for cholera infection, we conducted a prospective cohort study and followed household contacts of cholera patients for 7-days after the patient sought care. Clinical surveillance was based on reported symptoms of cholera and diarrhoea, and environmental surveillance was conducted through the collection of food and water samples. All analyses were stratified by the receipt of the hygiene kit and compliance of use.

Multivariate analysis suggested evidence of a dose-response relationship with increased kit use associated with decreased risk of suspected cholera: household contacts in the high kit-use group had a 66% lower incidence of suspected cholera, the mid-use group had a 53% lower incidence and low-use group had 22% lower incidence, compared to household contacts without a kit. Drinking water contamination was significantly reduced among households in receipt of a kit. There was no significant effect on self-reported diarrhoea or food contamination.

The integration of a hygiene kit intervention to case-households, may be effective in reducing cholera transmission among household contacts and environmental contamination within the household. Further work is required to evaluate other proactive localised distribution among patients and case-households or to households surrounding those case-households to optimise future cholera response programmes in emergency contexts.

Process evaluation

Cholera remains a leading cause of infectious disease outbreaks globally, and a major public health threat in complex emergencies. Hygiene kits distributed to cholera case-households have previously shown an effect in reducing cholera incidence and are recommended by Médecins Sans Frontières (MSF) for distribution to admitted patients and accompanying household members upon admission to health care facilities (HCFs).

This process evaluation documented the implementation, participant response and context of hygiene kit distribution by MSF during a 2018 cholera outbreak in Kasaï-Oriental, Democratic Republic of Congo (DRC). The study population comprised key informant interviews with seven MSF staff, 17 staff from other organisations and a random sample of 27 hygiene kit recipients. Structured observations were conducted of hygiene kit demonstrations and health promotion, and programme reports were analysed to triangulate data.

Between Week (W) 28-48 of the 2018 cholera outbreak in Kasaï-Oriental, there were 667 suspected cholera cases with a 5% case fatality rate (CFR). Across seven HCFs supported by MSF, 196 patients were admitted with suspected cholera between W43-W47 and hygiene kit were provided to patients upon admission and health promotion at the HCF was conducted to accompanying household contacts 5-6 times per day. Distribution of hygiene kits was limited and only 52% of admitted suspected cholera cases received a hygiene kit. The delay of the overall response, delayed supply and insufficient quantities of hygiene kits available limited the coverage and utility of the hygiene kits, and may have diminished the effectiveness of the intervention. The integration of a WASH intervention for cholera control at the point of patient admission is a growing trend and promising intervention for case-targeted cholera responses.

These two complimentary studies in the Democratic Republic of Congo (DRC) evaluated the effectiveness of hygiene kit distribution to admitted cholera patients and their households at health care facilities, and the implementation and receipt of the overall cholera response.

The study followed household contacts of cholera patients for 7-days after the cholera patient sought care and received the intervention, collected data on reported symptoms of cholera and diarrhoea, and collected environmental samples of food and water to test for contamination. One of the studies examined the effectiveness of the hygiene kit distribution on the incidence of cholera and diarrhoeal disease and on food and water contamination. The other study collected quantitative data on intervention reach and distribution and qualitative data on receipt of the intervention by the study population. This study examined the challenges and successes to intervention delivery and receipt by the population.

Integration of the hygiene kits at the point of admission of suspected cases is possible, and both an effective and promising intervention for case-targeted cholera control. There was a 66% lower incidence of cholera among the population who received and frequently used the hygiene kit. There was positive response, use and adherence to hygiene kits by households. However, there were barriers to the timely supply, inadequate availability and consequent limited coverage of the hygiene kits. Further work is required to identify ways to improve implementation and delivery of this promising intervention.

The research may help responding agencies decide what types of intervention to include in their emergency cholera response programmes.

Background

Cholera epidemics occur frequently in low-income countries affected by concurrent humanitarian crises. Evaluations of these epidemic response remains largely unpublished and there is a need to generate evidence on response efforts to inform future programmes. This review of MSF cholera epidemic responses aimed to describe the main characteristics of the cholera epidemics and related responses in these three countries, to identify challenges to the effectiveness and feasibility of different intervention strategies based on available data; and to make recommendations for epidemic prevention and control practice and policy.

Methods

Case studies from the Democratic Republic of Congo, Malawi and Mozambique were purposively selected by MSF for this review due to the documented burden of cholera in each of the countries, frequency of cholera outbreaks, and risk of concurrent humanitarian crises. Data were extracted on the characteristics of the epidemics; time between alert and response; and, the delivery of health and water, sanitation and hygiene (WASH) interventions. A Theory of Change for cholera response programmes was built to assess factors that affected implementation of the responses.

Results and conclusions

A total of 20 epidemic response reports were identified, 15 in DRC, one in Malawi and four in Mozambique. All contexts experienced concurrent humanitarian crises, either armed conflict or natural disasters. Across the three countries, median time between the date of alert and date of the start of the response by MSF was 23 days (IQR 14-41). Almost all responses targeted interventions community-wide, and all responses implemented in-patient treatment of suspected cholera cases in either established HCFs or temporary cholera treatment units (CTUs). In three responses, interventions were delivered as case-area targeted interventions (CATI) and four responses targeted households of admitted suspected cholera cases. CATI or delivery of interventions to households of admitted suspected cases occurred from 2017 onwards only. Overall, 74 factors affecting implementation were identified across reports including delayed supplies of materials, insufficient quantities of materials were delivered for effective programme delivery and limited or lack of coordination with local government or other agencies. Based on this review, the following recommendations are made to improve cholera prevention and control efforts: conduct rigorous and structured evaluations of cholera response programmes; explore improved models for epidemic preparedness, including rapid mobilisation of supplies and deployment of trained staff; invest in and strengthen partnerships with national and local government and other agencies as part of epidemic preparedness activities; and to standardise reporting templates within and across countries to provide consistent and accessible data by internal and external staff and collate learnings.

Based on this review, the following recommendations are made to improve cholera prevention and control efforts: conduct rigorous and structured evaluations of cholera response programmes; explore improved models for epidemic preparedness, including rapid mobilisation of supplies and deployment of trained staff; invest in and strengthen partnerships with national and local government and other agencies as part of epidemic preparedness activities; and to standardise reporting templates within and across countries to provide consistent and accessible data by internal and external staff and collate learnings.

Background

Globally, the risk of small-scale cholera outbreaks propagating rapidly and enlarging extensively remains substantial. As opposed to relying on mass, community-wide approaches, cholera control strategies could focus on proactively containing the first clusters. Case-area targeted interventions (CATI) are based on the premise that early cluster detection can trigger a rapid, localised response in the high-risk radius around one or several households to reduce transmission sufficiently to extinguish the outbreak or reduce its spread. Current evidence supports a high-risk spatiotemporal zone of 100 to 250 meters around case-households for 7 days.

We hypothesize that the prompt application of CATI will reduce household transmission and transmission in the wider ring. This will result in reduced incidence in the ring and reduced clustering of cases. The local focus of CATI will enable active case-finding and sustained uptake of interventions. This will result in prompt access to care for detected cases, and reduced mortality and community transmission.

Methods

We propose to evaluate the effectiveness of a CATI strategy using an observational study design during an acute cholera epidemic, with clearly-defined measures of the effectiveness of the CATI package. In addition, we intend to evaluate the feasibility, costs, and process of implementing this approach. The CATI package delivered by Médecins Sans Frontières’ (MSF) will incorporate key transmission-reducing interventions (including household-level water, sanitation, and hygiene measures, active case-finding, antibiotic chemoprophylaxis, and, single-dose oral cholera vaccination (OCV)) which aim to rapidly reduce the risk of infection in the household and in the ring around the primary case household. MSF will decide on the contents of the CATI package used, the radius of intervention and the prioritization strategy used if the caseload is higher than the operational capacity, based on national policies, the local context, and operational considerations. In scenarios where preventative vaccination has been recently conducted or is planned, CATI and its evaluation will focus on implementation before and during the mass campaign, or in areas where vaccination coverage was sub-optimal.

The study design is based on comparing the effects of CATIs that rapidly provide protection in averting later generations of cases when compared with progressively-delayed CATIs. A regression analysis will be used to model the observed incidence of enriched RDT-positive cholera as a function of the delay to intervention (in days). The delay will reflect the inverse strength of rapid response. Groups, as a function of their delays to intervention, will serve as internal controls.

Case-area targeted interventions (CATI) are based on the premise that early cluster detection can trigger a rapid, localised response in the high-risk radius around one or several households to reduce transmission sufficiently to extinguish the outbreak or reduce its spread.

We propose to evaluate the effectiveness of a CATI strategy using an observational study design during an acute cholera epidemic, with clearly-defined measures of the effectiveness of the CATI package. In addition, we intend to evaluate the feasibility, costs, and process of implementing this approach. The CATI package delivered by Médecins Sans Frontières’ (MSF) will incorporate key transmission-reducing interventions (including household-level water, sanitation, and hygiene measures, active case-finding, antibiotic chemoprophylaxis, and, single-dose oral cholera vaccination (OCV) ) which aim to rapidly reduce the risk of infection in the household and in the ring around the primary case household.

CATI has been highlighted as a major component of the GTFCC’s global research agenda. Therefore, conducting a rigorous prospective evaluation of the effectiveness of CATI, which includes OCV and explains the pathway to impact, is an important and timely question for outbreak control.

Cholera outbreaks caused by Vibrio cholerae are endemic in Kenya and the East Africa region accounting for nearly 10% of all cases reported from sub-Saharan Africa and the case-fatality rates remain above 2.5%, which is unacceptably high. Cholera is spread through consumption of fecally contaminated water or food. Investigating the relationship between cholera occurrence in terms of dominant hotspots and various environmental and human factors associated with the hotspots is important for managing cases and preventing future outbreaks. Whereas WASH interventions have been recommended by various studies as a control strategy for Cholera, the critical intervention pathways that have the most significant public health impact are not known.

The current research aims to study hotspots identified from previous outbreaks and from ongoing outbreaks in Kenya using drone technology to map areas for immediate sampling, exposure risks and most critical transmission pathways surveillance. Using SANIPATH techniques in identifying critical environmental and human factors associated with hotspots, we are deploying novel techniques including Whole Genome Sequencing (WGS) and bioinformatics partnering with relevant governmental agencies that will deploy our rapid detection and tracking techniques of these hotspots in a bid to innovatively establish preventive measures for infection emergence and spread. Data analysis will be done using basic descriptive statistics (percentages, means, standard deviations, modes) and the latest version of SAS software suite (SAS Institute Inc.) Ethical approval has been sought from Scientific Ethics Review Unit (SERU) in Kenya Medical Research Institute

Cholera is a disease caused and spread by germs that you get by eating or drinking contaminated food or water.

We are investigating areas in Mukuru slums that may harbor high concentration of these germs, e.g. sewers, open drainages, homesteads and water supply chains etc. We are using satellite imaging technologies to map areas of high risk for cholera, then get samples to investigate presence of these germs in the lab at KEMRI. This will help manage those with the disease as well as prevent future occurrence of the disease.

Work with local governments and communities to make evidence-based intervention decisions and co-design and implement WASH and/or OCV campaigns as appropriate for the local context; and

Build capacity in regional academic institutions and health ministries for applied public health research to strengthen cholera prevention and control programs.

Our project will use genomic data and a detailed understanding of pathogen evolution to deliver a robust, rapid, accurate and cost-effective pathogen detection kit for use in the field. Current methods are unsuitable for detection as they are slow, inaccurate and cannot be field deployed. Our work has already changed the basic understanding of how cholera spreads and identified high and low epidemic risks that are the cornerstones of disease prevention. By making robust molecular indicator kits adapted to field settings we are able to rapidly probe the likely behaviour of cholera strains and provide actionable data that can make a direct contribution to a major human health challenge.

This project will help fasten decision making in cholera outbreak control by indicating the risk associated with the type of cholera detected.

Diarrheal diseases are one of the most common causes of morbidity and mortality in the world today. It is estimated that a child dies of diarrhea approximately every 15-30 seconds; almost all of these deaths occur in the developing world. One of the, causative organisms, Vibrio cholerae, causes severe secretory diarrhea in humans. A prototypical mucosal infection, V. cholerae does not invade the intestinal epithelium and serves as an excellent model for the study of mucosal immunity and vaccination. The study focuses on defining the mechanisms of protective immunity to infection with V. cholerae so as to understand the requisites for the development of a protective cholera vaccine.

The central hypothesis of this proposal is that V. cholerae expresses specific proteins during early human infection, which generate immune responses that are protective on subsequent exposure; that these proteins may not be adequately expressed during colonization with currently available vaccine strains, and that these differences may explain the generally lessened efficacy of current vaccine approaches. As a result of this study, we hope to assess immune responses following cholera vaccination with the killed oral vaccines (Dukoral and/or Shanchol), and compare with responses to those seen following natural cholera. In order, to assess the duration of immunity to known cholera virulence factors, we will determine antigen-specific memory B cells circulating in human blood, to examine the longevity of B cell immunologic memory. To determine the mucosal immune responses, we will follow the immune responses using duodenal biopsies from patients recovered from cholera and correlate the duration of antigen-specific, antibody-secreting cells over a period of one year.

In addition to cholera patients, we will also study household contacts to assess innate and acquired immune responses early after exposure in household contacts of cholera patients, to determine correlates of subsequent protective immunity to cholera. The study planned is a continuation of investigations of immune responses in cholera (Pr#2005-030).

Yes, that impact the development of immune responses following cholera or that influence the development of clinical illness following exposure to the organism.

Burden

Cholera is life threatening disease that remains one of the major causes of deaths in the developing countries. Although more than 200 serogroups of V. cholerae reported so far, serogroup O1 and O139 are the major pathogenic strains. Serogroup O1 has two biotypes, classical and El Tor. The classical biotype caused first six cholera pandemics in the Ganges Delta of Bay of Bengal and the other parts of the world. The El Tor biotype of V. cholerae initiated the ongoing 7th pandemic in early 1960s. The El Tor biotype was displaced for a short while in late 1992 when an explosive cholera epidemic occurred by V. cholerae O139 synonym Bengal. O139 however, failed to continue as the predominant epidemic strain and thus V. cholerae El Tor continued to cause the ongoing 7th pandemic.

Knowledge gap

A retrospective study on V. cholerae strains isolated between 1991 and 1997 showed that the biotypes Classical, El Tor, and El Tor variants were involved in endemic cholera in Mexico and ET prototype (wild type) were involved in Peru. We are not aware about the present status of cholera bacteria in different parts of Latin America so; a follow-up study on V. cholerae isolated from 1998 to 2012 was designed.

Hypothesis

The V. cholerae strains causing endemic cholera between 1998 and 2012 in Mexico and other countries of Latin America might not be different in terms of biotype, phenotype, molecular, and phylogenetic properties compared with Asia and Africa.

Objectives

The aim of this study is to determine the prevalent sero-biotypes, molecular status and clonal nature of V. cholerae isolated in Mexico and other Latin American countries and compare those characteristics with the strains isolated from Gangetic Bengal and Africa.

Methods

150 V. cholerae strains (both clinical and environmental) which included 89 strains isolated in Mexico, 45 in Peru, 12 in Brazil, and 6 in Guatemala will be analyzed by culture method, serogrouping and antibiogram. V. cholerae strains will also be subjected to detection of marker genes such as ompW, wbeO1, wbfO139, ctxA and ctxB by PCR. Extensive molecular characterizations using multi-locus genome screening and DNA fingerprinting (phylogeny) by PFGE will also be done.

Outcome measures/variables

This study will generate valuable information on nature (clonal types) of cholera bacteria, their transmission patterns world-wide. This is important because updated information on phenotypic, molecular, and phylogenetic characteristics of V. cholerae associated with cholera in Mexico and other Latin American countries are lacking.

The V. cholerae strains causing endemic cholera between 1998 and 2012 in Mexico and other countries of Latin America might not be different in terms of biotype, phenotype, molecular, and phylogenetic properties compared with Asia and Africa.

Cholera is endemic in many lower- and middle-income countries (LMICs) due to persistent environmental reservoirs, poor sanitation, hygiene, and water services, compounded by humanitarian disasters. Community engagement and health system strengthening are two proposed pillars of the WHO Global Taskforce on Cholera Control (GTFCC) Roadmap 2030 to eradicate cholera in endemic countries. Health system strengthening interventions has shown positive impacts on health outcomes; and community engagement appears to facilitate lowered water-borne disease transmission rates in outbreak situations. However, specific barriers and facilitators for both concepts, and any interfacing factors are unclear. Therefore the objective was to identify and describe the facilitators and barriers concerning community engagement and healthcare system strengthening for cholera control as well as any factors acting at the interface of both interventions in LMICs.

The Arksey and O’Malley framework for scoping reviews was employed and three electronic databases (PubMed, CINAHL and Web of Science) were searched using database specific combinations of search terms representative of cholera, community, and healthcare system components. Documents in English, within the period 1990 to 2021, in LMICs and focusing on explicitly reasoned facilitators or barriers of health system strengthening, community engagement or the interface between were included. Data charting was completed using narrative descriptive analysis, followed by thematic analysis. Reporting was done in line with PRISMA-ScR guidelines.

Forty-four documents met the study predefined inclusion criteria and were included for the review. Documents covered a wide range of countries, with Haiti most often mentioned. Half of included documents related to Sub-Saharan African countries, 68% (30/44) to cholera endemic settings and 20.5% (9/44) to conflict or civil unrest settings. Thematic analysis identified three themes of facilitators and barriers for health systems strengthening: cooperation between stakeholders; capacity for task fulfilment; governance, supervision, and feedback; and insecurity. Two themes described Community engagement facilitators and barriers: trust building and social cohesion. Strong governance and capacity adaptation facilitated health system strengthening while community representatives and civic structures enabled community participation and empowerment. Stigma, communication strategies targeting personal characteristics, poor leadership, interfering socio-political factors and conflict acted as barriers to both concepts as well as the interface between.

Findings from this study suggest that insecurity, community representatives and poor governance with interfering socio-political factors influence community health system interactions and trust building and may impair intervention impact.

Cholera is an ongoing global health problem, especially in poor communities or refugee camps lacking water and sanitation services. To eradicate cholera the WHO Global Taskforce on Cholera Control (GTFCC) Cholera roadmap proposes health system strengthening and community engagement interventions. But it is not known how best to achieve these. To explore this gap a scoping review of facilitators and barriers to the two concepts was completed. This included searching electronic databases for relevant documents and analysing them. 44 documents were included with most concerning Sub-Saharan African countries and countries that have cholera as a long term problem, and some documents mentioned Insecurity and conflict. results showed that conflict, interfering social and political factors and poor leadership affected both health system and community engagement interventions. Health system strengthening was influenced by cooperation, capacity adaptation, supervision and feedback. Community engagement was improved through community representatives and organisations.

Awareness of facilitators and barriers to community engagement and what affects community-health system interactions can help to contextualise these to ensure the greatest chance of sustained community ownership of cholera interventions. Mitigating against barriers of health system strengthening interventions can help build resilient health systems.

We analyzed the estimated duration of immunity following cholera infection from available published studies. We searched Pubmed and Web of Science for studies of the long-term immunity following cholera infection. We identified 22 eligible studies and categorized them as either observational, challenge, or serological.

We found strong evidence of protection at three years after infection in observational and challenge studies. However, serological studies show that elevated humoral markers of potential correlates of protection returned to baseline within one year. Although with small sample sizes, three studies found that most participants with a subclinical infection from an initial challenge with cholera had a symptomatic infection when rechallenged with a homologous biotype, suggesting that a subclinical cholera infection may confer lower protection than a clinical one.

This review underscores the need to elucidate potential differences in the protection provided by clinical and subclinical cholera infections. Further, more studies are warranted to bridge the gap between the correlates of protection and cholera immunity. Understanding the duration of natural immunity to cholera can help guide control strategies and policy. 

The duration of natural immunity following a cholera infection is unknown. Studies using different methodologies have estimated this duration, obtaining very different asnwers depending on the methodology used (ranging from a few months to several years). Here, we reviewed all published studies and compared their estimated durations. We found three smaller studies that concluded that duration of immunity following an asymptomatic cholera infection is much shorter than immunity following a symptomatic infection.

Understanding the natural history of cholera infection, particularly the mechanisms responsible for long-term protection, are key to prevention, outbreak response, and cholera control. Our results point to the need to further investigate the duration of immunity based on the presentation of symptoms.

OVERCOME will establish a transnational consortium with multidisciplinary expertise for cross-sectoral collaborative research in creating innovative technological methodologies and applications, including observations/surveillance, Internet of Things, climate/weather forecasting, artificial intelligence, machine learning, and data analytics to strengthen our capacity in predicting the outbreaks of cholera and other water-related diseases. We will engage with stakeholders from academia, industry, governments, NGOs, coming from a wide range of sectors e.g. natural environment, health care, environment-economic, urban planning, utility services, disaster management, policy making, etc., and local communities in co-shaping the research questions and targeted outcomes. One example is that we hope to fill the gap between rainfall and runoff in cholera forecasting, as well as between floods and epidemiology. The team building and methodology defining in the first 12 months will enable the follow-up research in the second phase for delivering an ultimate holistic framework that supports these stakeholders in strategic planning and decision making to enhance societal resilience to climatic hazards. This will strengthen the capacity of vulnerable communities in minimising the negative impact of disasters, such as cholera, and associated health risks, which will improve country progress in addressing Sustainable Development Goals (SDGs).

OVERCOME consortium includes world-leading organisations to develop state-of-the-art research plans that integrate digital innovations in natural hazard and risk predictions in order to develop intervention strategies for strengthening the resilience of vulnerable communities against climate hazards and health impacts, including cholera and other water-related diseases.

The partners from the UK, Malawi, Mozambique, and Zimbabwe will contribute knowledge and skills in climate and meteorology, hydrology and water resources, flood forecasting, droughts, water quality, epidemiology and public health, smart technologies, data science, environmental science, Water, Sanitation and Hygiene (WASH), risk communication, disaster management, social and policy sciences, and socio-economics. The collaboration will combine multidisciplinary knowledge to develop a novel holistic framework to forecast the impact of floods/droughts and associated disease outbreaks. OVERCOME also has strong support from global experts and local major stakeholders. The external partners will steer research direction throughout the project, contribute their complementary knowledge, and engage the team with additional partners through their strong international networking.

OVERCOME consortium will co-design an innovate holistic framework to help governments and local authorities in the partnering countries more accurately identify the timing and locations where the hazards and diseases, including cholera, will hit.

This project focuses on defining O-specific polysaccharide (OSP) responses during cholera and development of vaccines protective against cholera and enteric infection.

Immune responses that mediate protection against cholera target the sugar (OSP) that coats the bacteria that causes cholera. Young children in particular do not develop high level or durable immune responses against this sugar after oral cholera vaccination. Understanding and improving these responses will be critical in development of next generation cholera vaccines that can protect young children against cholera, and that can be incorporated in EPI schedules.

Informs development of next generation cholera vaccines for use in children under 5 years of age.

Cholera is a major source of under 5 yrs. mortality globally; the existing oral vaccine is not effective for this age group. A Cholera Conjugate Vaccine (CCV) is under development with partnership between MGH Harvard (USA), Eubiologics & IVI (latter two in Korea) to address this need; it has the O-specific Polysaccharide antigen from Vibrio cholerae O1 Inaba El Tor strain conjugated to a recombinant tetanus toxoid heavy chain fragment (rTTHc) using a novel conjugation chemistry.

The study Drug Product materials are produced under a separate RIGHT Fund grant, using Drug Substance (DS; OSP–rTT-Hc Conjugate) produced through an optimized, scaled-up process at Eubiologics for use in preclinical animal toxicology study before its human clinical trial.

The proposal will help to complete (a) the toxicology study; (b) formulation of two additional DP batches for generating stability data; and (c) to complete an IND application for CCV’s phase 1 clinical trial.

Cholera is a disease of inequity that continues to disproportionately affect the world’s poorest and most vulnerable people. An oral cholera vaccine (OCV) is available and in use around the world, but it has lower efficacy in young children than in adults and a relatively short duration of protection necessitating re-vaccination every few years. We are developing a new conjugate vaccine that offers the promise of improved efficacy in all age groups, including those less than 5 years, and an extended duration of protection, thus reducing the requirements for repetitive vaccination to sustain population immunity. It can be implemented in place of OCV or as a complementary tool to prevent or limit outbreaks in high risk settings, and build enduring population immunity that will cost-effectively control cholera over the decades required to build definitive public health capacities in at risk countries.

Data from this project will enable the filing of an investigational new drug application to conduct a phase 1 trial of the CCV.

Our goal is to identify the best strategies to control the ongoing cholera outbreaks in the Republic of Yemen (ROY). To do so, we will evaluate previous interventions to inform and improve their implementation currently and in the future. These include use of oral cholera vaccines (OCV), water sanitation and hygiene (WaSH) strategies and acute watery diarrhea (AWD)/cholera-related messaging strategies.

Understand what interventions worked and what did not work to prevent cholera in Yemen. Also, recommend interventions that are possible.

Our findings of what works and why (or what did not work and why) will help guide policy and decision makers understand the factors impacting the success and challenges of the cholera integrated response plan intervention strategies for scale up programs. Consequently, we would have identified the optimal combination of interventions for AWD/cholera affected districts in ROY

There are currently two WHO pre-qualified oral cholera vaccines in the Gavi supported stockpile and available to eligible countries for emergency or routine preventive use. Both derive from the same basic technology and contain five antigenic components. This project seeks to simplify the formulation of the oral cholera vaccine to reduce the number of components and simplify the production. Guided by input from experts in cholera, vaccine developers and regulators, a simplified formulation will be produced and evaluated in a phase III, multicenter, observer-blinded, randomized, active controlled trial to determine immune non-inferiority, safety and lot-to-lot consistency of Oral Cholera Vaccine-Simplified (OCV-S) compared to ShancholTM in 1 to 40 year old healthy Nepalese participants. If successful, the simplified formulation will reduce product unit cost and expand production capability of manufacturers.

Oral Cholera vaccine is currently in high demand with limited supply. If successful, this formulation simplification will reduce unit cost and expand supply availability of all current manufacturers using this technology.

Introduction: Adamawa and Bauchi are cholera endemic states in the north-east region of Nigeria, each with local government areas classified as cholera hotspots. Ineffective implementation of multi-sectoral cholera interventions in both states could make obtaining the global target for cholera control in Nigeria out of reach. A major contributing factor to this challenge is fragility of the region due to persistent Boko Haram insurgency activities, often characterised by the destruction of health infrastruture and displacement of communities to areas with suboptimal living conditions. Given the complexity of disease control in such a fragile setting, this study aims to systematically examine the barriers and/or facilitators influencing the implementation of existing cholera interventions in these states.

Methods: The study will use a systems dynamic approach. First, we will conduct a health facility survey to determine the current health system capacity to support multi-sectoral cholera interventions, and conduct key informant interviews with purposely selected state and national cholera stakeholders to identify the context-specific facilitators and barriers to the implementation of cholera interventions in these states. We will then conduct nine group model building workshops (four in both the Adamawa and Bauchi states and one in Abuja) among cholera stakeholders similar to those recruited for the interviews.

Conclusion: By engaging diverse and relevant cholera stakeholders, including community members, this study has the potential to provide a rich understanding of context-specific factors influencing the implementation of multi-sectoral cholera interventions in a fragile region of Nigeria, with a view to achieve sustainable progress towards cholera control in the country.

Adamawa and Bauchi states are cholera endemic states in the north-east region of Nigeria, each with some local government areas classified as cholera hotspots or high burden areas. However, the prevailing activities of armed conflict, as perpetuated by Boko-Haram, in the region could make the implementation of multi-sectoral cholera interventions ineffective. Moreover, addressing disease burden in such fragile settings is particularly challenging. Thus, this study aims to systematically examine the barriers and/or facilitators influencing the implementation of existing cholera interventions in these states.

To achieve these objectives, the study will use a systems dynamic approach, by first conducting a health facility survey to determine the current health system capacity to support multi-sectoral cholera interventions, as well as conducting key informant interviews with purposely selected cholera stakeholders at various levels of government. These research activities will then be followed by a series of participatory workshops (four in both Adamawa and Bauchi states and one in Abuja) among participants with similar characteristics as those in the key informant interviews. It is worth noting that findings from the first phase of the study will be informing the workshop activities.

Overall, by engaging diverse and relevant cholera stakeholders, including community members, this study has the potential to provide a rich understanding of context-specific factors influencing the implementation of multi-sectoral cholera interventions in a fragile region of Nigeria, with a view to achieve sustainable progress towards cholera control in the country.

Nationally, the study would be providing context-specific findings, generated in collaboration with various cholera stakeholders including policymakers and community representatives. Globally, the study is designed around the GTFCC’s global strategic framework, thereby making the potential findings of direct relevance to cholera global stakeholders.

The project is to gain an understanding of the epidemiology of cholera in the Great Lakes Region – Africa to develop tailored prevention investment plans in identified hotspots of Uganda, Tanzania and Burundi.

Specifically, the project is designed to 1) identify hotspots in these countries, 2) develop factsheets on cholera to guide preparedness, 3) and prepare investment plans for for these hotspots. Notably, UNICEF has a method for hotspot mapping which is different from the GTFCC; thus maps using these two methods are presented and compared.

Analyze the epidemiology of cholera in Uganda, Tanzania, and Burundi to prepare hotspot maps and attempt to identify factors that influence cholera rates in these hotspot areas. Based on the identification of these hotspots, the project should prepare recommendations for cholera control using an integrated approach. Eventually, this should result in an investment plan.

The countries should be able to use this information in preparing their National Cholera Control Plans.

This collaborative project between Johns Hopkins University; University of Maryland; University of Florida, Ministry of Health, United Republic of Tanzania, M.A. Sante, Yaoundé, Cameroon, and the Nigeria Centre for Disease Control will describe the molecular epidemiology of cholera in Tanzania and Cameroon to determine the degree to which cholera in these countries originates locally or is introduced from outside and is
transmitted widely.

This study is attempting to characterize the epidemiology in these cholera endemic countries in Africa.

This study attempts to provide a more complete understanding of cholera epidemiology in Africa.

Validation of a new rapid test for cholera compared to standard culture and PCR.

This study will compare the results of a new dipstick test for cholera that detects only Vibrio cholerae serogroup O1 (but not serogroup O139) with the results of standard stool culture and PCR using stool specimens collected on filter paper.

Validation of a new dipstick rapid test will allow for more rapid detection of cases and potentially will allow for more rapid declaring of an outbreak.

This project will compare the vibriocidal titers in subjects who receive a second dose of oral cholera vaccine (Shanchol), two weeks, 6 months or 11.5 months after the first dose. The primary outcome is the geometric mean vibriocidal titer two weeks after the second dose. Additional follow-up serum samples will determine the persistence of the vibriocidal titers.

This will provide guidance when the second dose of OCV is delayed.

This project will evaluate the vibriocidal responses following receipt of oral cholera vaccine (Shanchol) when the second dose is given either 2 weeks or 6 months following the first dose. The primary outcome is the change in geometric mean vibriocidal titers two weeks after the second dose, but additional serum samples will be obtained to determine longevity of the increased titers.

Assurance of a non-inferior vibriocidal response when the second dose of OCV is delayed will provide guidance for timing of the second dose.