PROJECT SUMMARY In 2010, cholera was introduced in Haiti, resulting in over 800,000 cases of cholera and over 10,000 deaths. While the cholera epidemic in Haiti is the largest in over 25 years, it is far from an isolated event, and other large outbreaks have occurred in South Sudan, Sierra Leone, Tanzania, the Democratic Republic of the Congo, Iraq, Nigeria and most recently in Yemen where over 860,000 cases of cholera have occurred 2017. In addition to these epidemics, cholera is currently endemic in 47 countries where it often disproportionately occurs in young children. When cholera was introduced in Haiti, vaccination was not considered part of the standard public health response to cholera epidemics. During the first funding period of this project we showed that a new, lower-cost oral cholera vaccination was highly immunogenic in children and adults in Haiti, and that vaccination was feasible and effective in preventing cholera in Haiti. These studies have contributed to an improved understanding of cholera vaccines, which are now being deployed globally to more effectively prevent large cholera epidemics. Despite this progress in understanding cholera vaccines, there remains an urgent need to learn more about how to eliminate cholera in areas once it is already established in the environment. In this proposal, we address questions that will improve upon current programs to eliminate human cholera transmission in such endemic areas. Our aims will leverage public health activities undertaken by our team and partners, including an innovative cholera elimination program in Haiti which will include vaccination with household water treatment and safe storage interventions. In this study, we will use novel methods to understand how both symptomatic and asymptomatic breakthrough cholera infections occur even after an intervention to eliminate cholera. We will also determine whether such integrated vaccination and water related interventions impact more broadly on the health of young children in the community. We will do this by looking at their nutritional health, intestinal health, and infection with specific intestinal bacteria, and seeing how these relate to vaccination and improvements in water quality at the household level. Given our team’s experience in Haiti, our involvement in providing cholera treatment and prevention services, our multidisciplinary scientific approach, and our contribution to global cholera policy, we are well poised to address these critical questions, which are urgently needed to inform the most effective approach toward achieving the World Health Organization’s goal of the elimination of cholera transmission as a global threat by 2030.

PROJECT NARRATIVE Assessing measures to eliminate cholera in Haiti will inform future public health strategies to eliminate the threat of cholera transmission globally. This project will also improve our understanding of how cholera elimination programs may broadly impact on the health of young children beyond their effect on cholera alone.