EPN Covers West Nile Virus Cases
Posts from Equine Protenction Network covering outbreaks of the West Nile Virus. For up to the minute information and the newest press releases, please go to the EPN website. Link is under favorites.
Horse-Positive For West Nile Virus
Sat Sep 2 18:35:45 2000
The first equine case of West Nile virus (WNV) in the United States this year has been confirmed by USDA?APHIS Veterinary Services' National Veterinary Services Laboratories (NVSL). The positive case was diagnosed in a horse on Staten Island (Richmond County), New York.
Significant WNV activity has already been reported from Staten Island this year, including 4 human cases, at least 40 wild birds, and at least 64 mosquito pools.
The positive equine WNV case was an approximately 26 year?old gelding that became ill on August 17, and got worse over the next three days. A serum sample was collected prior to euthanasia of the animal by a New Jersey veterinary practitioner on August 20 and sent to the N.J. Division of Animal Health laboratory for WNV testing. A positive hemagglutination inhibition test was found at that lab on August 23 and serum was forwarded to NVSL for WNV confirmation. No tissues were available for testing as the horse was rendered soon after euthanasia. NVSL confirmed the diagnosis via positive results on an IgM?capture enzyme?linked immunosorbent assay (ELISA) on August 25 and a plaque reduction neutralization test (PRNT) on August 28.
A veterinarian from the New York State Department of Agriculture and Markets investigated the Staten Island case premises August 24. A second horse on the same premises as the confirmed case horse was found not to be clinically ill, but blood was collected for testing for WNV exposure (subclinical infection). Mosquito traps were also placed on the premises by the City of New York to help evaluate the local mosquito population. The premises is in a residential, urban area, but several houses in the area have large lots on which a few horses may be kept.
Mosquito control activities, including ground spraying for adult mosquitoes, have been ongoing on all of Staten Island on a regular basis since early August when the first human case was detected.
USDA/APHIS information about West Nile Virus is available from:West Nile (active link down below)
If you have any questions, please contact USDA, APHIS, Veterinary Services, Emergency Programs staff at 301-734-8073, 800-940-6524, or EMOC@USDA.GOV. Please forward this information to other Federal, State and industry counterparts as necessary.
Horses in New Jersey and Rhode Island Confirmed Positive for West Nile
Two additional horses have been confirmed positive for WNV infection.
The Cases are the second and third equine cases of 2000 and are located in
Washington County, Rhode Island, and Cape May County, New Jersey. The
first equine case in 2000, confirmed August 28, was a horse on Staten
Island (Richmond County), New York.
These new cases are the first equine cases of WNV in the United States
Outside of New York State. The positive case in Rhode Island was a
2-year-old mare; the positive case in New Jersey was a 6-year-old gelding.
Both of these horses were confirmed positive for WNV by polymerase chain
reaction (PCR) on brain tissue, and by IgM-capture enzyme-linked
immunosorbent assay (ELISA) and plaque reduction neutralization test
(PRNT) on serum. Virus isolation
on brain tissue of both horses is underway.
USDA, APHIS recommendations to horse owners to reduce risk of WNV
infection Are to reduce mosquito breeding sites and decrease exposure to
Recommendations are available from the APHIS website:
Other WNV Developments
WNV in Humans
The first human case of WNV infection in New Jersey was reported
As of September 2, the total number of confirmed or probable human
cases of WNV infection in 2000 is now eight; none of the patients has
died, although at least one is in critical condition.
WNV in Bats
Three bats were found to be positive for WNV infection in Albany
County, New York. This is the first report of WNV-positive bats in the
U.S. They were Big brown bats living in an Albany house and showed no
significant signs of illness.
The news release from the New York Department of Health is available at
If you have any questions, please contact USDA, APHIS, Veterinary
Emergency Programs staff at 301-734-8073, 800-940-6524, or
Please forward this information to other Federal, State and industry
counterparts as necessary.
This APHIS website has a wealth of info on WNV, including the cases last year in NY. Ages of the horses, locations, dates of infection,etc.