Case-area targeted interventions (CATIs) among household contacts and neighboring households after defining cholera hotspot areas in Bangladesh: The potential impact on cholera control

Outbreaks or epidemics of cholera are unpredictable and can occur both in endemic and nonendemic areas depending on environmental conditions, natural calamities, climate change, or any humanitarian crisis where sanitary infrastructure is disrupted. The current supply of oral cholera vaccine (OCV) is limited, and the available OCVs are prioritized for cholera outbreaks, making preventive OCV campaigns difficult to carry out. Rapid detection of cholera cases and targeting their household contacts and neighbors by case- area targeted interventions (CATIs) may effectively avert cholera cases and deaths within a short period during epidemics. OCV was predicted to be an effective short term single intervention in CATI 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 neighbors in the reduction of the incidence of cholera and explore the genome analysis, AMR, gut microbiota, and immune response to V. cholerae antigen from different hotspots. We will follow the participants for three years. Our data will provide evidence of the effective dosing schedule, and pathogen genomics to improve disease surveillance and demonstrate if the current OCV is effective against the shifting lineage to predict AMR genes.