- From ProMED-mail promed@promed.isid.harvard.edu Carla
Everett, Information Officer Texas Animal Health Commission Box l2966 *Austin,
Texas 78711 ceverett@tahc.state.tx.us
-
- Preliminary tests on a sick horse that was euthanized
on Sat 29 Jun 2002 near Katy in far west Harris County, indicate that the
animal was infected with West Nile virus (WNV), a form of "sleeping
sickness" first detected in Texas in 2 dead blue jays on 18 Jun 2002
on the north west side of Houston. According to the Texas Department of
Health (TDH), another 29 infected birds have since been found.
-
- "We were notified today (Wed 3 Jul 2002) that tests
run on samples of the horse's blood and spinal fluid were positive for
WNV. The tests were run both at the Texas Veterinary Medical Diagnostic
Laboratory (TVMDL) in College Station, and at the National Veterinary Services
Laboratory (NVSL) in Ames, Iowa," said Dr Linda Logan, Texas' state
veterinarian and executive director for the Texas Animal Health Commission
(TAHC), the state's livestock health regulatory agency. "The NVSL
is running additional confirmation tests on the blood samples, but more
than likely, we are seeing Texas' first case of WNV in a horse. Diagnosing
WNV infection must be based on laboratory confirmation, as the signs of
the disease, including staggering or the inability to rise, can mimic other
diseases, including rabies, or other encephalitic diseases, such as western
equine encephalitis (WEE) and eastern equine encephalitis (EEE)."
-
- WNV has spread to 20 of the United States, following
the migratory flight patterns of birds along the eastern seaboard and west
as far as Texas. In 2001, 738 horses, donkeys, or other members of the
equine family were diagnosed with the disease in the US, and about 20 per
cent of the animals had to be euthanized, due to the severity of their
illness. "Blue jays, crows, and more than 70 other species of birds
can carry the virus, but it is the mosquito that puts the disease cycle
in motion," explained Dr. Logan. "After feeding on infected birds,
mosquitoes ingest the virus, and about one per cent of the pests then become
infected and capable of spreading the virus to horses or humans. There
have been no documented cases of animals or humans spreading the disease.
Dogs and cats appear to be resistant to the disease."
-
- "Home and stable owners should take precautions
to prevent mosquito bites," said Dr Joe Garrett, a veterinarian with
the TDH's Zoonosis Control Division. "We continue to work with other
agencies to urge horse owners to have their animals vaccinated against
WNV, and with the diagnosis of this disease in the Houston area, all possible
preventive efforts are important to stop the spread of this disease,"
said Dr Richard Ferris, area-veterinarian-in-charge for the US Department
of Agriculture's Veterinary Services in Texas.
-
- "We are investigating other potential cases in horses
in Harris County and are awaiting test results. If you live in the Houston
area, protect your horses from mosquitoes. While a vaccine is available
for horses, the animal must receive 2 doses of WNV vaccine 3 to 6 weeks
apart, and full protection does not begin until at least 4 to 6 weeks after
the second dose of vaccine is administered," he said. "I'd urge
owners to take action now to get horses protected." "If your
horse becomes ill and goes off feed, sways, develops head tremors, muscle
twitches or cannot rise, contact your veterinarian, so he or she can collect
and send in samples to us for diagnostic testing," said Dr Lelve Gayle,
executive director of the TVMDL. Laboratory confirmation of cases is particularly
important for tracking the movement of WNV within the state.
-
-
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-
-
- Comment
-
- From G Meade
7-6-2
-
- Source: United States Department of Agriculture; Animal
and Plant Health Inspection Service.
-
- Reporting Period: 2001; January through 31 December
-
- USDA-APHIS reported that in 2001 there were 738 cases
of clinical West Nile Virus infection reported in horses in 130 counties
in 20 States. Of the 738 reported cases 651 cases were verified through
diagnostic testing at the National Veterinary Services Lab of USDA-ASPIS.
Of those - 640 were classified as 'confimred' cases and 11 as 'probable'.
-
- Of 470 horses for which an outcome has been reported
156 (33.2%) died or were euthanatized.
-
- Equine Deaths - by State (2001)
-
- CT 4, DE 1, FL 82, GA 22, IL 1, IN 1, KY 6, LA3, MA
1, MD 1, MS 7, NH 1, NJ 15, NY 2, NC 2, PA 4, TN 1 and VA 2.
-
- NOTE: Circumstances have prevented me from being 100%
involved - manufacture/distribution of product (insect repellent)these
last two years. Just as I noted the tremendous increase interest for all
natural repellent following NY outbreak 1999...what I've noted recently
has been requests/interest for 'bulk' (concentrate) repellent. (for equine
use; barns stables, etc)(I live in an area that's an 'odd' mix. That is,
on one side of the county you have 'regular folks' (middle class-working
population) and on the other side of the county you have 'gentry folk'
(exclusive golf/country clubs, polo ground, etc.)
-
- I believe the 'numbers' are being under-reported with
regards to the equine cases. Or, perhaps, the media is not picking up on
the numbers that are being reported and thereby it's not getting to the
mainstream press. However, based on what I'm hearing -orders/requests received...equine
WVN is of major concern to owners, breeders and trainers. As mentioned
earlier...I operated on a limited basis (last year) but from all indications
- this year will surpass previous years COMBINED - strictly 'word of mouth'
in so much as i have not placed ad-done promotions.
-
- If I had to hazard a guess - I'd say WNV has hit cattle
as well as dogs - but DVM's are not looking (nor expecting) the disease.
(?)
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