West Nile virus is beginning to peek out from the mysterious hiding places where it overwintered since an outbreak in late 1999. Five additional birds have been found dead with the virus– four in New York, and one in New Jersey. Officials believed the virus was present in sentinel chicken flocks in Delaware, but the discovery was a false alarm.

West Nile virus (WNV) is a type of encephalitis spread by the bite of an infected mosquito. The virus first was found in birds last fall, and had never been experienced before in the Western Hemisphere. The disease caused illness and death in both horses and humans. For more WNV coverage, visit our web page dedicated to historical facts and news on West Nile at https://thehorse.com/TopicSearch/Default.aspx?n=West+Nile+Virus+(WNV)&nID=6&ID=79.

Two crows in New York were an adult male and female found on May 22. They were submitted from the same area in Rockland County. The New York State Health Department confirmed the presence of the virus on June 9. An additional two birds were found in Rockland County and confirmed positive in late June– a crow from the Clarkstown area, and a blue jay from the Orangetown area. The New Jersey report involves a dead crow that was found May 30. WNV was confirmed in that bird by the Centers for Disease Control (CDC) on June 8.

In Delaware, blood tests of three sentinel chicken flocks were suspected to be positive for WNV by a quick test done by state agencies. This “preliminary” test, which detected presence of the virus in the birds, was developed this year to detect mosquito-borne diseases rapidly and has proven helpful, but not always conclusive. As mentioned before, the CDC determined that the birds were not positive for West Nile