Dengue Transmission Pattern Shifts and Climate-Urbanization Nexus in South Asia

South Asia faces a critical epidemiological transition where dengue transmission is extending beyond traditional seasonal windows, driven by the convergence of climate warming, erratic precipitation patterns, and rapid urbanization. According to the WHO South-East Asia Regional Office, dengue cases increased significantly in 2025, with Bangladesh reporting 102,562 cases and early 2026 travel alerts remaining active across the region. The interplay between urban heat islands and climate change is fundamentally altering mosquito breeding cycles, transforming dengue from a seasonal monsoon-associated disease into a year-round health threat that challenges existing surveillance and control frameworks.