Comparison of vector competence for West Nile virus of colonized populations of Culex tritaeniorhynchus from Southern Asia and the Far East

Abstract

Seven colonized stocks of Cx. tritaenoirhynchus from different geographic areas of Southern Asia and the Far East were assayed for susceptibility to WN virus infection by membrane feeding and by intrathoracic inoculation. Infected females were also tested for their ability to transmit virus to baby mice. No geographic pattern of differential susceptibility to WN virus infection was apparent from the experiments; however, the per os ID(50) of one strain from Khulna, Bangladesh, was over 10-fold greater than the ID(50)'s of stocks from Karachi, Pakistan and Sendai, Japan. No difference in susceptibility was found by parenteral inoculation of virus. Likewise, ≥ 90% of infected females from all the colonies were able to transmit virus.