Improving Health Outcomes in Vulnerable Population of Bangladesh Rohingya Refugee Camp: The Role of Wastewater Surveillance

Limited clinical infrastructure in high-density humanitarian settings hampers the monitoring of infectious diseases. Wastewater surveillance (WS) offers a non-invasive and cost-effective approach to monitor pathogen transmission at the community level. This study implemented WS in three Forcibly Displaced Myanmar Nationals (FDMN) camps and Cox’s Bazar municipality from October 2022 to October 2023. To detect the targeted four pathogens: Rotavirus, Vibrio cholerae, Salmonella Typhi, and SARS-CoV-2, total 612 wastewater samples were analyzed using qPCR. These pathogen concentrations were correlated with weekly aggregated acute watery diarrhea (AWD) cases reported through WHO’s Early Warning, Alert and Response System (EWARS). Rotavirus was detected in 93% of samples, SARS-CoV-2 in 61%, Vibrio cholerae in 56%, and Salmonella Typhi in 3%. The municipality showed higher detection of Vibrio cholerae (73%) and Salmonella Typhi (6%), whereas Camp 9 exhibited the highest SARS-CoV-2 prevalence (73%). For SARS-CoV-2, the seasonal peaks were observed from May to August and for Vibrio cholerae between March to May. A weak but significant positive correlation (r = 0.22, p < 0.05) was identified between Vibrio cholerae concentration in WS and AWD cases. Additionally, 4% of samples carried the Vibrio cholerae (ctxA) toxin gene while vaccine-derived Rotavirus strains were identified in 2- 3% of samples. These findings validate the feasibility of wastewater surveillance in humanitarian settings. Integrating WS with clinical data can strengthen outbreak preparedness and direct targeted public health interventions in resource-limited settings.