USU lab tests for West Nile virus
Utah State University’s Veterinary Diagnostic Laboratory conducts all animal testing for West Nile virus in Utah.
Tom Baldwin, director of the Veterinary Diagnostic Laboratory, said, “Our role is to deal with agriculture and to provide information to public authorities to inform of any possible risk to humans.”
Though no human exposures to the West Nile virus have developed in Utah, professionals prepare for a statewide increase for next year.
Humans infected with the virus may experience no illness or mild flu-like symptoms. It is estimated one in 150 people with the virus will experience severe, potentially life-threatening symptoms, according to the Centers for Disease Control and Prevention Web site at www.cdc.gov.
Michelle Korth, an epidemiologist from the Utah Department of Health, explained that the months of August and September are the peak season for the virus.
“If Utah is like Colorado, Nebraska, and other states, over 75 percent of their cases occurred during these months,” Korth said. “[The exposure] could possibly be overwhelming next year. We are preparing for that increase, but we don’t know what will happen.”
Earl Rogers, from the State Veterinary’s Office, said there may be an increase in cases in Utah next year and possibly a few this year.
“Last year, Colorado was in about the same condition that we are in this year with the exception of a few cases in humans. Now, they have had over 800 human cases,” Rogers said.
Baldwin said, “Some diseases cross over between humans and animal species: Rabies is an example. We are the lab that detected the West Nile virus in Utah, and [like other testing,] report our findings to the State Veterinary’s Office and the Department of Health.”
Baldwin said that while some birds such as the crows, ravens, jays, hawks and others of those species have been tested in Cache County, most samples come from the sentinel chicken plans they have in areas of exposure throughout the state.
“Chickens’ immune systems produce antibodies which are detectable in blood testing,” Baldwin said.
He said the presence of these antibodies tells whether the chicken has been exposed to the virus.
“This was the means of knowing that the virus had first moved to the state of Utah,” Baldwin said.
Rogers explained the current tracking of the virus in Utah. He said it has been identified in a total of nine horses in four counties: Emery, Uintah, Duchesne and Wayne. The virus was also detected in the sentinel chickens in Carbon and Emery Counties.
There have been mosquito pools in Carbon and Utah counties that tested positive, but there has not been any detection in dead birds or in humans throughout the state.
Baldwin said the number is increasing, especially in horses. The VDL does a continued activity check of the sentinel chickens as well as some horse samples.
“Horses are more susceptible than humans, and the virus is active in the counties neighboring Colorado,” Baldwin said.
A vaccine is available for horses, which should protect them.
“There is always concern for public health. Mosquito control is the best tool for humans,” Rogers said.
Korth said the virus is not contagious from mammal to mammal, only from an infected mosquito or from an infected blood transmission which is very rare, and now protected by screening.
A human vaccine is being developed, but could take two to three years, Rogers said.
Korth said people should take precautions since a vaccine is not available on the market for humans yet. Prime hours for infected mosquitoes are from dawn to dusk.
“Avoid bites by using repellent with DEET and by wearing long sleeves and pants to reduce exposure,” she said. “Eliminate standing water and mosquito breeding sites.”
Korth said there is no need to stop being active.
“Go hiking, have barbecues, just take precautions. There is no treatment [for the virus], so prevention is the key,” she said.
– julia@cc.usu.edu