English: Infection chain and cycles of Japanese encephalitis virus (JEV). Wading and water birds are natural hosts and carriers of JEV. Culex and Aedes mosquitos transfer JEV between birds and to other species. Through seasonal migration, the birds spread JEV between tropical, subtropical, and temperate regions and across the sea. Wild and domesticated pigs play a special role in the infection chain, as they are carriers and amplifiers of JEV through vector-free transmission of JEV between them. Humans are dead-end hosts with about 1% succumbing to encephalitis, usually with subsequent severe deficiencies or fatal outcome.