Dead crow density and West Nile virus monitoring, New York.
New York State used the health commerce system to monitor the number of West Nile virus (WNV) human disease cases and the density of dead crows. In each year from 2001 to 2003 and for the 3 years combined, persons living in New York counties (excluding New York City) with elevated weekly dead crow densities (above a threshold value of 0.1 dead crows per square mile) had higher risk (2.0-8.6 times) for disease caused by WNV within the next 2 weeks than residents of counties reporting fewer dead crows per square mile. This type of index can offer a real-time, relatively inexpensive window into viral activity in time for prevention and control. Changes in reporting, bird populations, and immunity may require that thresholds other than 0.1 be used in later years or in other areas.
Eidson
Millicent
M
New York State Department of Health, Albany, New York, USA. mxe04@health.state.ny.us
Schmit
Kate
K
Hagiwara
Yoichiro
Y
Anand
Madhu
M
Backenson
P Bryon
PB
Gotham
Ivan
I
Kramer
Laura
L
D000818:Animals; D046368:Crows / Q000821:virology*; D004784:Environmental Monitoring / Q000379:methods*; D062665:Epidemiological Monitoring; D006801:Humans; D009518:New York / Q000453:epidemiology; D012307:Risk Factors; D014901:West Nile Fever / Q000453:epidemiology*; D014902:West Nile virus / Q000302:isolation & purification*