Longitudinal studies of Japanese encephalitis virus infection in vector mosquitoes in kurnool district, Andhra Pradesh, South India

Abstract

A 4-yr (2002-2006) entomological study was carried out in Kurnool district, Andhra Pradesh state, south India, to identify the mosquito vectors of Japanese encephalitis virus (family Flavi- viridae, genus FUwivirus, JEV). In total, 37,139 female mosquitoes belonging five genera and 18 species resting on vegetation were collected in villages and periurban areas at dusk. Mosquito species composition and pattern of JEV infection in mosquitoes varied in periurban and rural areas. In periurban area, Culex gelidus Theobald was abundant, msking up 49.7% of total catch followed by Culex tritaeniorhynchus Giles (44.5%). In rural area, Cx. tntamiorhynchus was predominant, making up 78.9% of total catch followed by Culex quinquefasciatus Say (10.8%), Anopheles subpietus Grassi (7.1%), and Gc. gelidus (1.1%). In light trap collections, Cx. gelidus and Cx. tntamiorhynchus predominated in periurban and rural areas, respectively. Of 50,145 mosquitoes screened JEV isolations were made only from Cx. gelidus and Cx. tritaeniorhynchus. Based on high abundance and frequent JEV isolation, Cx. tritaeniorhynchus was found to be the principal vector in both areas, whereas Cx. gelidus plays a secondary vector role in periurban areas only. © 2009 Entomological Society of America.