WYOMING — The Wyoming Department of Health (WDH) announced Monday that this West Nile virus (WNV) season has been more intense than usual, with 20 cases reported and one death among Wyomingites this year.
“This is clearly Wyoming’s most active West Nile virus season in at least a decade and it does not appear to be over yet,” WDH Epidemiologist Courtney Tillman said in a statement. “It remains important to avoid mosquito bites to help prevent illness with this virus, which can sometimes be quite serious.”
An older Fremont County woman died from the illness this year. Twelve of the 20 reported cases have involved neuroinvasive symptoms. Cases have been reported from Campbell, Fremont, Goshen, Laramie, Natrona, Park, Platte, Sheridan and Washakie counties. Mosquito pools and animals from around the state continue to test positive for WNV, according to WDH.
According to Tillman, it’s likely that many others have been sick from WNV without realizing the cause.
“It’s been estimated that for every confirmed neuroinvasive case there may be roughly 30 fever cases,” Tillman said. “Many, if not most, of these cases have not been identified with testing.”
Teton County has yet to report any positive human or animal cases this year, but WDH data indicates that one pool of mosquitos in Teton County has tested positive for the virus, out of 50 tested local pools. According to the data, upwards of 200 pools of mosquitos in Wyoming have tested positive for the virus in 2023.
According to WDH, the virus first appeared in Wyoming in 2002. Since then, case numbers have varied widely. In 2003, 393 cases were reported in the state, with nine people dying. Other years pass with zero West Nile virus deaths.
West Nile virus is transmitted by mosquitoes when they feed on infected birds and then bite people, animals or other birds. Crows, ravens, jays, raptors, owls and sage grouse are particularly susceptible to the disease.
Most infected people show no symptoms, but some experience fever, headache, body aches, skin rash and/or swollen lymph nodes. Some cases develop into West Nile neuroinvasive disease, which presents such symptoms as severe headache, fever, neck stiffness, stupor, disorientation, coma, tremors, convulsions and/or paralysis.
WDH recommends keeping in mind “the five D’s” during mosquito season:
- DAWN and
- DUSK – Mosquitos prefer to feed at dawn or dusk, so avoid spending time outside during these times.
- DRESS – Wear shoes, socks, long pants and a long-sleeved shirt outdoors. Clothing should be light-colored and made of tightly woven materials.
- DRAIN – Mosquitos breed in shallow, stagnant water. Reduce the amount of standing water by draining and/or removing.
- DEET – Use an insect repellent containing DEET (N, N-diethyl-m-toluamide). When using DEET, be sure to read and follow label instructions. Picaridin (KBR 3023) or oil of lemon eucalyptus can also be effective.
Learn more from the WDH about West Nile virus at www.badskeeter.org.
