Pratyay Hasan, Tazdin Delwar Khan, Mohammad Saiful Islam, Mohd Arifuzzaman, Mohammad Emdadul Haque
Urban hyperendemicity, characterized by a high case volume, coupled with the emerging coastal per-capita risk, necessitates tailored interventions. Intensive vector control is essential in Dhaka, while early-warning surveillance should be implemented in coastal districts.
BACKGROUND: Dengue has shifted from Dhaka-centric to nationwide in Bangladesh.
AIM: To quantify spatiotemporal patterns and identify high-risk clusters across all 64 districts from 2021 to 2025, and, extending previous reports with data from 2025, this study aims to observe an ongoing shift in per-capita risk hotspots.
METHODS: Retrospective ecological study of the Directorate General of Health Services (DGHS) aggregate yearly data on suspected and laboratory-confirmed dengue admissions (n = 637,626 cases). Incidence per 100,000 population was calculated using 2022 census projections with 1.12% annual growth. Global (Moran's I) and local (Getis-Ord Gi∗) spatial autocorrelation and prospective space-time scan statistics (SaTScan) were applied.
RESULTS: National incidence: 76.4/100,000/year. 2025 rate-adjusted Moran's I = 0.328 (p = 0.001). Raw-case hotspots: Greater Dhaka; population-adjusted hotspots: Jhalokathi, Barguna (coastal). High-rate space-time cluster (2024-2025): Dhaka, Manikganj (RR = 3.13, p = 0.001). Dhaka O/E = 4.31 (RR = 6.38). Two low-rate clusters (north, southeast).
CONCLUSION: Urban hyperendemicity, characterized by a high case volume, coupled with the emerging coastal per-capita risk, necessitates tailored interventions. Intensive vector control is essential in Dhaka, while early-warning surveillance should be implemented in coastal districts.