Mosquito distribution and West Nile virus infection in zoos and in important sites of migratory and resident birds, Thailand

Objective: To investigate the distribution of mosquito species in the zoos and in important sites\udof migratory and resident birds and evaluate West Nile virus (WNV) infection in mosquito species.\udMethods: Mosquitoes distribution investigation was carried out bimonthly from January 2009\udto December 2010 in five areas of birds, Thailand by using Centers for Disease Control, light\udtraps, and gravid traps. Mosquitoes were identified, pooled into groups of up to 50 mosquitoes by\udspecies, places and time of collection and tested for WNV infection by viral isolation and reverse\udtranscriptase polymerase chain reaction. Results: A total of 66 597 mosquitoes comprising 26\udspecies in 8 genera were collected. The five most abundant mosquito species collected were\udCulex tritaeniorhynchus (79.3%), Culex vishnui (8.2%), Culex sitiens (6%), Culex quinquefasciatus\ud(3.3%) and Anopheles peditaeniatus (1.1%). All 1 736 mosquito pools were negative for viral isolation\udand reverse transcriptase polymerase chain reaction. Conclusions: This study provides new\udinformation on number of mosquito species present and their relative abundance. Although\udour study found no evidence of WNV in the avifaunal sources of Thailand, mosquito active\udsurveillance should be continuously conducted. The cooperation between related organizations\udis needed for early detection of WNV disease and development of effective veterinary and public\udhealth policies in this region