An older Platte County woman represents the first and only human case of West Nile virus (WNV) reported to the Wyoming Department of Health (WDH) so far this year.

West Nile virus
Culex quinquefasciatus

“Year to year WNV activity can vary widely and is tough to predict,” said Dr. Tracy Murphy, state epidemiologist with WDH. “We’ve seen cases as early as May and as late as October, with big swings in the number of reported cases.” 

In Wyoming last year, 41 human WNV cases, including one death, were reported. Since WNV first appeared in Wyoming in 2002, reported human cases each year have ranged from two with no deaths to 393 and nine deaths.

Murphy noted most people infected with WNV don’t have symptoms. Among those who become ill, symptoms include fever, headache, body aches, skin rash and swollen lymph nodes. A very small number develop West Nile neuroinvasive disease with symptoms such as severe headache, fever, neck stiffness, stupor, disorientation, coma, tremors, convulsions and paralysis.

Mosquitos spread WNV when they feed on infected birds and then bite people, animals and other birds. The “5 D’s” of West Nile virus prevention include:

DAWN and 2) DUSK – Mosquitos prefer to feed at dawn or dusk, so avoid spending time outside during these times.
3) DRESS – Wear shoes, socks, long pants and a long-sleeved shirt outdoors. Clothing should be light-colored and made of tightly woven materials.
4) DRAIN – Mosquitos breed in shallow, stagnant water. Reduce the amount of standing water by draining and/or removing.
5) DEET – Use an insect repellent containing DEET (N, N-diethyl-m-toluamide). When using DEET, be sure to read and follow label instructions. Other insect repellents such as Picaridin (KBR 3023) or oil of lemon eucalyptus can also be effective.