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Most western South Dakota counties report horses infected with virus
By Steve Miller, West River Editor
West Nile Virus now has spread to the Rapid City area and more than 50 counties in South Dakota, with three people and 270 horses infected.
One person each in Miner, Lyman and Potter counties is infected with the disease,
according to a news release from the South Dakota Department of Health.
Nationally, 453 people have been diagnosed with West Nile Virus. Twenty-one of those have died, the Health Department reported.
All West River counties except Custer, Mellette and Shannon now report horses with West Nile, according to Dr. Sam Holland, state veterinarian. Butte County has 21 horses with the disease; Pennington, eight horses; Meade, seven; and Haakon, five.
Four or five horses in the Rapid City area have tested positive for the viral disease, according to Dr. Wesley Wood of the Animal Clinic in Rapid City. Other horses in the area are suspected of having the disease.
Wood said he didn't know of any horses here that have died of the disease. About a third of the horses that show signs will die of West Nile Virus, he added.
Holland said he doesn't know how many horses have died in the state.
As of Tuesday, 61 birds had been found with the disease in 24 counties, although only one, Stanley County, is west of the Missouri River.
The virus first was detected in South Dakota in July in Brown County.
As the level of infection among animals intensifies, the risk of human illness increases, according to Dr. Lon Kightlinger, state epidemiologist.
West Nile is primarily a bird disease, with crows especially susceptible, Kightlinger said in a news release. Mosquitoes become infected by feeding on an infected bird and can pass the virus to humans, horses or other hosts when they bite.
People who become infected may develop mild flu-like symptoms such as fever, headache, body aches and occasionally swollen lymph glands or a rash. In rare cases, West Nile may cause inflammation of the brain, Kightlinger said.
There is no vaccine for humans. Wood said there appears to be enough vaccine to handle the horse population in the Rapid City area, even though there has been a run on the medicine in the past six weeks. "We haven't had a problem getting it ordered in."
Wood said the Animal Clinic has sold 1,500 doses of the vaccine. Some of those are for second or third shots. Veterinarians recommend two doses three to six weeks apart to prevent the disease. Two doses cost about $35.
Local veterinarians recommend that horse owners vaccinate their horses, even though mosquito season will end in a few weeks.
Wood said West Nile now is well established in the region, but vaccinations should slow down its spread over the next few years. "It's a virus. You don't just wipe those things out overnight," he said.
Holland said horses diagnosed with West Nile and treated have a survival rate of 70 percent to 80 percent. "Even horses that undergo paralysis and go down, a good percentage of those survive."
The treatment includes anti-inflammatory agents, fluids and vitamins.
"The sooner they get it treated, the better," Holland said. People should pay attention if their horses slow down markedly or are not as active as usual. "In 24 hours, they can be paralyzed," he said.
Meanwhile, South Dakota will receive a $201,594 federal grant to fight West Nile Virus, Health Secretary Doneen Hollingsworth said.
The money will be used for more testing, more education about how to reduce the risk and training for local officials involved in mosquito control.
Although the risk of West Nile for humans is low, Kightlinger said people should take precautions to protect against mosquito bites. They include:
* Get rid of old tires and other containers where water can accumulate and serve as a breeding ground for mosquitoes.
* Avoid outdoor activities at dusk and dawn when mosquitoes are most active.
* Wear long-sleeved shirts and long pants in mosquito-
infested areas.
* Use mosquito repellents containing DEET.
* Use bug lights and screen doors and windows.
Communities in affected
areas should consider adult-mosquito control, the Health Department said.
Today, the South Dakota State University Cooperative Extension Service will offer
another session of its
mosquito-control training from noon to 4 p.m. MDT over the Dakota Digital Network and Extension's V-tel Network. For more information about the training, call 688-4596.
Posts: 771 | From: Farmington | Registered: Oct 2000
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ATLANTA — Government health officials are warning doctors that the West Nile virus can cause acute paralysis after the mosquito-borne virus apparently caused six people to become paralyzed.
The Centers for Disease Control and Prevention urged doctors to test patients for West Nile if they report sudden, painless paralysis but do not appear to have had a stroke.
The warning came as health officials confirmed that the West Nile virus can apparently be transmitted through blood transfusions and said that all blood donations will probably be screened for the virus as soon as a test can be developed.
The most serious effect of infection — life-threatening brain inflammation — occurs in only a small percentage of cases, mostly among the sick or elderly. But most of the reported paralyses, in Mississippi and Louisiana, have occurred among middle-aged people who were previously healthy, CDC medical epidemiologist Jim Sejvar said.
Some of these victims lost the use of an arm or leg; others needed ventilators to help them breathe.
A CDC report said the symptoms can be confused with a condition known as Guillain-Barre syndrome. There is no known way to prevent West Nile paralysis, but Sejvar said treatments for Guillain-Barre syndrome may be harmful to patients who actually have West Nile.
Health officials also suggested Thursday that the virus can survive in donated blood for days.
A woman in Mississippi caught West Nile after receiving transfusions from three infected donors. CDC doctors called that case "highly suspicious" and said that West Nile "probably can be spread by transfusion."
Previously, doctors were not sure whether it was possible to spread West Nile through blood, although a Georgia case in which donated organs spread the virus to four recipients in August raised that possibility.
Dr. Jesse Goodman of the Food and Drug Administration said that all blood donations will probably be screened for the virus as soon as a test can be developed. He could not predict how long it would take to develop such a test or how much it would cost.
"What we're trying to do here is jump-start this process," he said.
But screening for the virus could prove difficult. West Nile is much harder to detect than a virus such as HIV because there are relatively small amounts of West Nile in tainted blood.
Furthermore, a screening would have to detect the virus itself — not just antibodies the body produces in response — because the virus spends several days in the blood stream before symptoms show up.
Blood banks said they expected the FDA's announcement. Dr. Louis Katz, president-elect of industry group America's Blood Centers, said the important question is not whether West Nile can be transmitted through blood, because it probably can, but whether it's a threat big enough to warrant testing all donations for it.
"Does it rise to the level of appropriate screening? That's what we have to figure out," Katz said, adding that some diseases known to be spread through transfusion aren't screened because they're so rare.
West Nile was first detected in the United States just three years ago. The CDC has reported more than 1,700 human cases of West Nile virus so far this year, including 84 deaths.
Most people who become infected with the virus suffer no ill effects at all; others develop only flu-like symptoms.
Researchers also point out that not all patients who receive tainted blood will become infected with West Nile. The CDC reported a July case in which a 55-year-old woman received contaminated blood after an orthopedic procedure but never tested positive for the virus.
While repeating that the benefits of blood transfusions far outweigh the risks of catching West Nile, Goodman said patients seeking elective surgery may want to talk with their doctors about delaying the procedure or donating their own blood to be used later on themselves.
Posts: 771 | From: Farmington | Registered: Oct 2000
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