Date palm sap to human mortality: A review of Nipah virus epidemiology, transmission, clinical manifestations, and public health response in Bangladesh

Nipah virus (NiV) infection is a highly fatal zoonotic disease and remains a major public health concern in Bangladesh. This narrative review comprehensively examines the epidemiology, outbreak pattern, transmission dynamics, clinical manifestations, ecological drivers, public health interventions, surveillance systems, therapeutic progress, and vaccine development related to NiV infection in Bangladesh. The review was conducted through a comprehensive analysis of published literature and relevant reports from 2001 to February 2026, retrieved from PubMed, Scopus, and Google Scholar. During this period, Bangladesh reported 348 confirmed NiV cases across 35 districts, with 250 deaths and an overall case fatality rate of 71.84%. Outbreaks were concentrated mainly in the central and northwestern regions, commonly referred to as the “Nipah belt.” The principal route of transmission was consumption of raw date palm sap contaminated by greater Indian fruit bat ( Pteropus medius ), while person-to-person transmission through close contact with infected individuals also played an important role. Clinical features were dominated by fever, unconsciousness, respiratory distress, headache, vomiting, and other neurological symptoms. Seasonal outbreaks were strongly associated with winter sap collection, bat feeding behavior, environmental conditions, and cultural practices. Although bamboo skirts, awareness campaigns, boiling of sap, and hospital-based surveillance have contributed to prevention efforts, sustained community adoption remains limited. Bangladesh still lacks approved vaccines, specific antiviral therapy, rapid point-of-care diagnostics, and advanced biosafety infrastructure. Expanding surveillance, improving early diagnosis, implementing ecological interventions, and advancing vaccine and therapeutic research are essential to reduce future spillover and human-to-human transmission.