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

Abstract

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