A first note on Japanese encephalitis virus isolation from Culex quinquefasciatus Say in Northern West Bengal

摘要

Japanese encephalitis (JE) is endemic in many parts of India including the state of West Bengal. InWest Bengal, the first major outbreaks of JE occurred in the districts of Bankura and Burdwan in1973. The Culex vishnui subgroup of mosquitoes has been implicated as major vectors of JE.However in India, JE virus (JEV) has been isolated from 16 species of mosquitoes. DuringSeptember 2011, JE cases were reported from four districts -Jalpaiguri, Darjeeling, Dinajpur andCooch Behar of West Bengal (North). Adult mosquitoes were collected, identified, pooled andscreened for JEV using antigen capture ELISA. Out of 279 mosquito pools tested, one pool of Cx.pseudovishnui and three pools of Cx. quinquefasciatus were found positive for JEV. The ELISApositive pools were further confirmed as JEV by insect bioassay (Toxo-IFA). Two pools of Cx.quinquefasciatus were confirmed as JEV. This represents the first report of JEV isolation from Cx.quinquefasciatus in West Bengal.