West Nile Appears Again

West Nile virus is beginning to peek out from the mysterious hiding places where it overwintered since an outbreak in late 1999. Three birds have been found dead with the virus—two in New York, and one in New Jersey.

Two crows in New York were an adult male and female found on May 22 , and were submitted from the same area in Rockland County. The New York State Health Department confirmed the presence of the virus on June 9. The New Jersey report involves a dead crow which was found May 30, and WNV was confirmed by the Centers for Disease Control (CDC) on June 8.

The virus had also been detected in a dead red-tailed hawk in Bronxville, N.Y. in February, and in adult mosquitoes in Queens, N.Y., during January and February.

West Nile virus (WNV) is a type of encephalitis spread by the bite of an infected mosquito. The virus was found first 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.

“The potential exists for impact on the horse industry,” says Randall Crom, DVM, staff veterinarian for the United States Department of Agriculture (USDA) Animal and Plant Heath Inspection Service (APHIS), and coordinator for West Nile virus issues. “(The incidence of findings) does not mean that there will be human or equine cases, nor does it not mean there will be cases. The impact of this finding is hard to assess. Hopefully people won't overreact,” he says. The discovery is an indication that increased vector surveillance and control is working, and the millions of dollars funded by Congress, CDC, and other concerned agencies for these purposes is a worthwhile investment.

Crom believes that since the birds were discovered in late May, there might have been some dead birds that were collected during the time which elapsed during testing, and these birds might test positive. “I do expect there will be more findings, now that we have initial findings,” he said.

In Rockland County, NY, Crom explains that officials have not found any West Nile-positive mosquitoes, but he believes there must be some present. The positive crows were confirmed to have lived in Rockland County for awhile, so it is a likely speculation that there are positive mosquitoes in that county. “As for the bird in New Jersey, (where it picked up the virus), I would not speculate,” says Crom.

“I expect there will be other cases found, if not soon, certainly at some point during the summer,” he adds.

Birds are one of the possible routes of West Nile's entry into this country. Anyone aware of unusual wild bird deaths is encouraged to contact a state veterinarian or epidemiologist.

“Hopefully vector control will prevent any human or equine cases from taking place,” says Crom.”

About the Author

Stephanie L. Church, Editor-in-Chief

Stephanie L. Church, Editor-in-Chief, received a B.A. in Journalism and Equestrian Studies from Averett College in Danville, Virginia. A Pony Club and 4-H graduate, her background is in eventing, and she is schooling her recently retired Thoroughbred racehorse, Happy, toward a career in that discipline. She also enjoys traveling, photography, cycling, and cooking in her free time.

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