Japanese Encephalitis: Vaccine Preventable Diseases Surveillance Standards

Overview

Japanese encephalitis ( JE) is one of the most common encephalitides worldwide, with an estimated 68 000 cases and 13 20–600 400 deaths annually (1). The disease is caused by a mosquito-borne flavivirus and is found across south and east areas of Asia (currently 24 countries with JE virus transmission).

JE virus is transmitted to humans through the bite of infected Culex mosquitoes, which lay their eggs in irrigated rice paddies and other pools of stagnant water. Pigs and birds serve as amplifying vertebrate hosts. Humans are believed to be dead-end hosts, as viremia is too low to infect feeding mosquitoes.