A pre-monsoon entomological survey by the Institute of Epidemiology, Disease Control and Research has identified 14 wards in Dhaka with Breteau indices above 20, the threshold the World Health Organization considers a marker of high transmission risk. Several of those wards sit along the new metro alignment, where construction sites and uncovered foundation pits have created persistent breeding habitats.
The survey, shared with BHRF in summary form, recorded the highest indices in Banasree, Khilgaon, and parts of South Keraniganj — neighbourhoods that did not appear in the 2024 high-risk list. IEDCR researchers argue this geographic shift is consistent with how Aedes aegypti has been adapting to dense, heterogenous urban environments rather than confining itself to traditional inner-city pockets.
"The signal we are reading from this survey is that we are very likely to see a second peak before September unless larviciding ramps up immediately," said an IEDCR scientist who works on the entomology programme.
The two city corporations have stated that fogging schedules have been revised based on the survey's data and that ward councillors have been instructed to coordinate with sanitary inspectors. Independent vector experts, however, say fogging alone will not move the needle — source reduction and larviciding in construction lots are the proven interventions.
BHRF will publish the full ward-level breakdown once the IEDCR releases its public report.
