Dengue fatality, health seeking behavior and spatiotemporal dynamics in nonendemic regions of Bangladesh during the 2023 outbreak

Dengue, a neglected tropical disease, is a major global public health challenge, especially in low- and middle-income countries like Bangladesh. The 2023 dengue outbreak, the deadliest in Bangladesh’s history, revealed significant geographic expansion into non-endemic areas and highlighted systemic healthcare challenges. This study investigates the spatio-temporal dynamics of the outbreak, case fatality patterns, and health-seeking behaviors associated with mortality. We analyzed dengue surveillance data from the Directorate General of Health Services for 2019–2023 to examine district-level trends. Spatial hotspot analysis was conducted using ArcGIS and the Getis-Ord Gi* statistic. To address the lack of patient-level data in official reports, detailed information on 71 fatal cases was extracted from electronic newspaper reports, capturing socio-demographics, referral patterns, and care-seeking behavior. Descriptive and inferential analyses were performed using SPSS. In 2023, hospitalized dengue cases outside Dhaka were double those reported inside the capital, with persistent hotspots identified in southern districts such as Chattogram, Barisal, and Pirojpur. The overall case fatality rate was 0.6%, disproportionately higher among females and the elderly ( p < 0.01). Nearly half of the patients who died (47.9%) sought care only after clinical deterioration, and 50.7% were referred across multiple hospitals. Mortality within three days of hospitalization was more common outside Dhaka (63.3%) than inside (57.1%), reflecting limited access to specialized care. The 2023 dengue outbreak highlighted a fundamental geographic shift and systemic weaknesses in healthcare access and awareness. Strengthening surveillance in newly affected regions, improving district-level diagnostic and critical care capacity, and addressing delays in care-seeking through targeted community education are urgent priorities to reduce mortality in future outbreaks.