Archive for Sunday, September 23, 2001

WKD-State begins surveillance for West Nile virus

September 23, 2001


West Nile virus, first seen in New York in 1999, has permeated all the New England states and has been confirmed as far west as Iowa, Illinois and Tennessee.

Though the virus -- spread by infected mosquitoes -- hasn't yet reared its head in Kansas, public health officials and scientists recently began West Nile surveillance with the help of a grant from the Centers for Disease Control and Prevention.

"There's no way to predict exactly when a disease will migrate to any given geographic region," said Mike Heideman, communications director for the Kansas Department of Health and Environment. "We think it's best to be prepared if and when the virus does strike Kansas."

Researchers at KDHE and Kansas State University have been collecting and testing mosquitoes from across the state and will begin limited testing of dead birds the first of the year.

The virus

States are seeing West Nile first in dead birds, mostly crows and blue jays, said Gail Hansen, KDHE state public health veterinarian and deputy state epidemiologist.

That's because the mosquitoes most likely to carry the virus -- Culex spp -- prefer birds over mammals.

"A horse or human would be a second meal choice," Hansen said.

In humans, the virus can cause anything from mild illness to West Nile encephalitis, or brain inflammation, which is usually a mild disease but can be fatal, she said.

Symptoms progress from flu-like -- headache, swollen glands, muscle aches -- to typical signs of encephalitis, including confusion, difficulty speaking and possibly coma. No human vaccine or specific treatment exists for West Nile encephalitis or any other form of viral encephalitis, but medicine can be used to treat the swelling and fight off infection.

Elderly people seem most likely to be severely affected by the virus, Hansen said.

A bite from an infected mosquito hardly spells guaranteed illness in humans, however.

"Probably less than 1 percent of people who get bitten by a mosquito with West Nile virus even get ill," Hansen said.

The CDC has documented more than 80 cases of human infection, most in the New York City metro area. At least nine of those people have died.

Tracking movement

Kansans should know right away if the virus penetrates the state.

Scientists at Kansas State recently began collecting mosquitoes from traps across the state, sorting them by species and using sophisticated tests to detect the virus.

No virus has been found so far, said Roman Ganta, assistant professor of diagnostic medicine and pathobiology at Kansas State.

If the laboratory detected the virus, it would send the remaining sample to the CDC for verification. Once confirmed, the result would be announced publicly and appropriate precautions would be passed along, Ganta said.

Kansas officials are not asking the public to collect and freeze freshly dead birds to send in for testing -- a practice in some states where the virus has been around awhile.

"That has not proven to be effective until the virus has come up in an area," Heideman said.

For now, the advice if you find a dead bird is to put it in a bag and dispose of it, Hansen said. Although there is no evidence the virus can be spread from bird to person or person to person, it's best to wear gloves when handling potentially infected birds.

To stunt the progression of West Nile virus, Hansen said, people should avoid keeping stagnant water around the house. Water left sitting in bird baths, dog dishes, pool covers, old tires and elsewhere is a ripe breeding ground for mosquitoes that carry the virus.

"The best way for Kansas to keep from getting West Nile virus in our animals and ourselves is to keep the number of mosquitoes that transmit the virus to a minimum," she said.

-- Staff writer Mindie Paget can be reached at 832-7187.

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