Japanese Encephalitis in Bangladesh: A Decade of Hospital-Based Sentinel Surveillance, 2007-2016

Japanese encephalitis (JE) is a mosquito-borne flavivirus disease amplified by pigs and transmitted by Culex mosquitoes breeding in irrigated rice paddies -- a One Health disease at the intersection of livestock husbandry, agriculture, and human health. This study compiles a decade of hospital-based sentinel surveillance data for Bangladesh into a single reproducible summary. No public API or dashboard exists for this disease, and no second published source was found to cross-validate the data against -- disclosed explicitly, unlike the companion HPAI, rabies, and Nipah virus analyses in this series. Key findings: (1) of 6,525 tested acute meningitis-encephalitis syndrome patients at four sentinel hospitals (Rangpur, Rajshahi, Chittagong, Khulna), 548 (8%) were confirmed JE cases, 2007-2016; (2) cases spanned 36 of 64 districts (56%), concentrated in the northwest; (3) 193 cases (35%) were aged 15 years or younger; (4) cases were sharply seasonal -- 436 (80%) had onset July-November, peaking in October, consistent with monsoon-driven Culex mosquito breeding in rice paddies; (5) approximately 50% of pigs in the Rajshahi catchment were JEV-seropositive by age 3, direct evidence of the amplifying-host cycle; (6) the apparent case rise after 2010 coincides with the Rangpur site joining surveillance that year, likely reflecting expanded capacity rather than purely rising incidence. Data source: transcribed with full citation from Paul et al. (2020, International Journal of Infectious Diseases, doi:10.1016/j.ijid.2020.07.026). All analysis code and data are available at: https://github.com/khalilurrrahmanridoykhan/bangladesh-je-2007-2016