Case-area Targeted Interventions (CATIs) Among Household Contacts and Neighbouring Households After Defining Cholera Hotspot Areas in Bangladesh: The Effectiveness of OCV and Potential Impact on Cholera Control

Background (brief):

1. Burden: Annually, 2.8 million cases and 95,000 deaths due to cholera are estimated to occur in cholera-endemic countries of Asia, Latin and Central America, and sub-Saharan Africa. The risk of cholera infection within the household and also around the households of cholera cases is higher than in the overall population. Outbreaks of cholera are unpredictable and can occur both in endemic settings and nonendemic areas depending on environmental conditions, climate change, or any humanitarian crisis where sanitary infrastructure is being disrupted. New phenotypes and genotypes of V. cholerae strains are constantly evolving with outbreaks, resulting in an increased risk of antimicrobial resistance (AMR).
2. Knowledge gap: Standard cholera outbreak response and traditional vaccination campaign is time consuming, costly and usually delayed. A rapid response comprising an early detection of cholera case, hotspot identification and delivery of a rapid response to households around the case could reduce the transmission of disease. But it is not established that whether this early detection of cases and rapid intervention will reduce cholera transmission, also what number of oral cholera vaccine (OCV) will effectively reduce the transmission.
3. Relevance: Availability of OCV is scarce but necessary for rapid response as it an effective short-term single intervention to shortened the epidemic period and cholera cases. This study aims to evaluate the effectiveness of the CATI approach (single/two doses at 1-month intervals) among household contacts and their neighbours in the reduction of the incidence of cholera