Update: West Nile Virus Activity—Northeastern United States, January-August 7, 2000

SURVEILLANCE PROGRAMS INITIATED IN response to the 1999 West Nile virus (WNV) outbreak have detected increased transmission in the northeastern United States. 1 Seventeen states along the Atlantic and gulf coasts, New York City (NYC), and Washington, D.C., have conducted WNV surveillance and are reporting to CDC. 1 Surveillance for WNV infection includes monitoring of mosquitoes, sentinel chicken flocks, wild birds, and potentially susceptible mammals (e.g., horses and humans). 2 This report summarizes findings of this surveillance system through August 7, 2000.Avian morbidity and mortality surveillance has identified 188 WNV-infected birds from 34 counties in four northeastern states; 111 (59%) have been reported since August 1.These include 128 birds fromNewYork(Albany,Broome,Columbia,Dutchess,Erie,Franklin,Nassau,New York, Niagara, Onondaga, Orange, Putnam, Queens, Rensselaer, Richmond, Rockland, Schenectady, Suffolk, Ulster, Warren, Washington, and Westchester counties), 54 from New Jersey (Bergen, Essex, Hudson, Middlesex, Monmouth, Passaic, and Union counties), four from Massachusetts (Middlesex, Norfolk, and Suffolkcounties),andtwofromConnecticut (Fairfield and Tolland counties).In-fectedspeciesreportedinclude147American crows (78%) and 23 blue jays (12%).Infections also have been reported in the red-tailedhawk,fishcrow,housesparrow, American robin, merlin, song sparrow, Canada goose, great blue heron, north-1236