感染症と治療ジャーナル

抽象的な

Japanese Encephalitis and its Epidemiology

Malhotra S, Sharma S, Kumar P and Hans C

Japanese encephalitis (JE) is among the most common cause of viral encephalitis in human beings and is found worldwide. JE, a zoonotic disease, is caused by JE virus (JEV), a mosquito-borne flavivirus and belongs to the family Flaviviridae. About 1% of human JEV infections result in JE, but 20–30% of these cases are fatal and 30-50% of survivors have significant neurologic or psychiatric sequelae. WHO estimated that approximately 67 900 JE cases occur annually in the 24 JE-endemic countries with an overall incidence of 1.8 per 100 000 population and 75% of these cases occur in children aged 0-14 years, which gives an estimated overall annual incidence of 5.4 per 100 000 in this age group. Five genotypes of JEV (1 to 5), based on structural protein sequences, with geographically distinct distributions, have been described. Diagnosis of JE can be made by virus isolation in cell/ tissue culture, antigen detection, and antibody detection. There is no specific treatment of JE, and only supportive care is provided to patient thus prevention of JE is considered as an important intervention in JE. Hence a strong surveillance system along with implementation of high quality vaccination program for children is the key ingredients to reduce the number of JE cases in endemic areas.