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• The World Health Organization recommends the use of oral cholera vaccines in cholera control efforts. • We conducted a case-control study of the cholera vaccine, Euvichol® in Haiti. • Two-dose Euvichol® vaccine effectiveness was 69%. • Euvichol® can serve as one component of comprehensive cholera control efforts. The World Health Organization recommends the use of oral cholera vaccine (OCV) in cholera control efforts. Euvichol®, pre-qualified in 2015, is the leading component of the Global OCV stockpile, but data on its field effectiveness are limited. To evaluate Euvichol® vaccine effectiveness (VE), we conducted a case-control study between September 2018 to March 2020 following an OCV campaign in November 2017 in Haiti. Cases were individuals with acute watery diarrhea. Stool samples were tested by culture and real-time polymerase chain reaction of the Vibrio cholerae ctxA gene. Cases were matched to four community controls without diarrhea by residence, enrollment time, age, and gender, and interviewed for sociodemographics, risk factors, and self-reported vaccination. Cholera cases were analyzed by conditional logistic regression in the VE study. Non-cholera diarrhea cases were analyzed in a bias-indicator study. We enrolled 15 cholera cases matched to 60 controls, and 63 non-cholera diarrhea cases matched to 249 controls. In the VE analysis, eight (53%) cases reported vaccination with any number of doses compared to 43 (72%) controls. Adjusted two-dose OCV VE was 69% (95% CI –71 to 94%). Between 10-27 months after vaccination, Euvichol® was effective and similar to Shanchol™, suggesting that it can serve as one component of multi-sectoral comprehensive cholera control. [ABSTRACT FROM AUTHOR]

In Haiti in 2017, the prevalence of serum vibriocidal antibody titers against Vibrio cholerae serogroup O1 among adults was 12.4% in Cerca-la-Source and 9.54% in Mirebalais, suggesting a high recent prevalence of infection. Improved surveillance programs to monitor cholera and guide public health interventions in Haiti are necessary. [ABSTRACT FROM AUTHOR]

Background: Food insecurity has been independently associated with developing cholera and there is an inverse relationship between national food security and annual cholera incidence. However, the factors that mediate the risk of cholera among food insecure households remain largely unexplored. Methodology and principal findings: In a cross-sectional survey of rural households in Haiti, we explored the role of food behaviors (i.e., dietary choices and food-handling practices) as mediators of cholera risk among food-insecure families. We generated a series of multivariable regression models to test hypothesized associations between the severity of food insecurity (measured by the Household Hunger Scale), hygiene and food behaviors, and history of severe, medically-attended cholera. Moderate household hunger (Adjusted Odds Ratio [AOR] 1.47, 95% Confidence Interval (CI) 1.05–2.04; p = 0.021) and severe hunger (AOR 2.45, 95% CI 1.45–4.15; p = 0.001) were positively associated with a history of severe, medically-attended cholera compared with little to no household hunger. Household hunger was positively associated with three behaviors: antacid use, consumption of leftover non-reheated food, and eating food and beverages prepared outside of the home (i.e., at a restaurant or from a vendor). Consumption of outside food items and antacid use were positively associated with a history of cholera. Conclusion: Our findings suggest that food behaviors may mediate the association between food insecurity and cholera and contribute to an understanding of how interventions could be designed to target food insecurity as part of cholera prevention and control. Author summary: Food insecurity has been found to be a risk factor for cholera at the household and national level, however the mechanism through which food insecurity may increase the risk of cholera remains unknown. In a large cross-sectional survey of 1072 households in rural Haiti, we observed a robust independent association between food insecurity—defined as a persistent lack of access to food in adequate quantity or quality and measured by the Household Hunger Scale—and reported history of severe, medically-attended cholera. The association was dose-dependent, with the odds of reported cholera increasing linearly with household food insecurity. Household food insecurity was associated with three high-risk behaviors: antacid use, consumption of leftover non-reheated food, and eating food and beverages prepared outside of the home. Two high-risk behaviors—including antacid use and consumption of food and beverages prepared outside of the home (i.e., at a restaurant or from a vendor)—were independent risk factors for cholera. High-risk food practices may be one causal pathway by which food insecurity increases risk of developing cholera. In this study, we provide a framework for future longitudinal and qualitative studies to investigate whether interventions that target food insecurity could also reduce cholera risk among populations who face a high burden of both conditions. [ABSTRACT FROM AUTHOR]