JAPANESE ENCEPHALITIS VIRUS INFECTION IN MOSQUITOES AND ITS

Japanese encephalitis is a serious public health problem in India. The Japanese encephalitis virus (JEV) is maintained in nature by a complex cycle that involves pigs as amplifying hosts, ardeid birds as reservoirs and mosquitoes as vectors. The Culex vishnui subgroup of mosquitoes consisting of Cx. tritaeniorhynchus Giles, Cx. vishnui Theobald and Cx. pseudovishnui Colless have been implicated as major vectors of JE. However in India, JEV has been isolated from 16 species of mosquitoes (Table). Isolation of virus from a species does not provide sufficient proof of its vectorial competence. The main criteria to consider a species of mosquito as a vector are that the population should be high and stable during the epidemic season; long survival rate of the mosquito so that the extrinsi