Emerg Infect DiseidEmerging Infectious Diseases1080-60401080-6059Centers for Disease Control115855422631767Research ArticleWest Nile virus in overwintering Culex mosquitoes, New York City, 2000.NasciR. S.rsn0@cdc.govSavageH. M.WhiteD. J.MillerJ. R.CroppB. C.GodseyM. S.KerstA. J.BennettP.GottfriedK.LanciottiR. S.CDC-DVBID, PO Box 2087, Fort Collins, CO 80522, USA.Jul-Aug200174742744

After the 1999 West Nile (WN) encephalitis outbreak in New York, 2,300 overwintering adult mosquitoes were tested for WN virus by cell culture and reverse transcriptase-polymerase chain reaction. WN viral RNA and live virus were found in pools of Culex mosquitoes. Persistence in overwintering Cx. pipiens may be important in the maintenance of WN virus in the northeastern United States.