Methodology Study

To evaluate the effectiveness of the CATI approach among household contacts in the reduction of cumulative incidence of cholera and explore the genome analysis and immune response of V. cholerae antigen from different hotspots in Dhaka city, cholera cases will be enrolled by rapid diagnostic test (RDT) from the diarrhoeal patients coming to icddr,b Dhaka hospital. Hotspots will be defined as the households (HHs) surrounding the RDT-positive cholera case (around 20-40m radius). The 'Case area targeted interventions' (CATI) will be given by administrating Oral Cholera Vaccine (OCV) with either one dose or two doses of OCV 1 month apart among household contacts (≥1-year age and non-pregnant women) and contacts of the contacts residing in the adjacent HHs. The passive surveillance for cholera will be followed using the icddr,b hospital, and other health facilities. Data on each individual's states of the clusters (e.g., susceptible, exposed, infectious, or recovered) will be tracked throughout the 3 years study follow-up.

The study aims to assess the effectiveness of various commercial and non-hazardous buffers for the storage of human gut fecal samples over time. This evaluation will be conducted by comparing the performance of these buffers against directly frozen samples using metaproteomic analysis. The study is motivated by the need for standardized protocols for sample preservation in metaproteomic research, particularly focusing on protein preservation in fecal samples. By investigating proteomic, taxonomic, and functional identifications, the research seeks to provide insights into the reliability of these buffers as storage solutions. Additionally, the study plans to explore inter- and intra-individual variabilities at the proteome level by periodically collecting fecal samples from volunteers, complementing existing knowledge in metaproteomics. Overall, the study addresses a critical gap in the field and has the potential to enhance reproducibility and comparability across metaproteomic studies