First Wyoming case of West Nile virus reported

With Wyoming’s first case of human infection from West Nile virus (WNV) confirmed for the year, the Wyoming Department of Health (WDH) has issued a reminder to protect yourself from mosquito bites.

“Recent reports confirm the first human infection of West Nile virus this season involving a Goshen County resident,” said Courtney Tillman, epidemiologist with WDH.

“It is important to remain alert and protect yourself from mosquito bites during the last months of summer while mosquitoes remain active.”

According to CDC data, this year has seen 174 total cases across the nation, with 113 of them evolving into neuroinvasive cases. A total of 30 states have reported WNV so far in 2024.

For most people, WNV will not cause any symptoms. However, if you do become infected, you may experience fever, headache, body aches, skin rash and swollen lymph nodes.

For the small number of people who develop neuroinvasive disease, the symptoms can include severe headache, fever, neck stiffness, stupor, disorientation, coma, tremors, convulsions and paralysis.

Most people will recover completely, though the fatigue and weakness can last for weeks or months. About one in 150 people, though, will develop a serious illness affecting the central nervous system, such as encephalitis or meningitis, and about one of every ten of those people dies.

“To protect yourself from WNV, it’s important to prevent mosquito bites,” Tillman said.

The ‘5 Ds’ of WNV prevention include:

1) DAWN and 2) DUSK – Mosquitoes 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 loose-fitting and made of tightly woven materials.

4) DRAIN – Mosquitoes breed in shallow, stagnant water. Reduce the amount of standing water by draining and/or removing objects with standing water.

5) 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.

WNV first appeared in Wyoming in 2002, according to the WDH. Reported annual human cases have ranged from one case with no deaths to 393 and nine deaths in 2003.

In 2023, Wyoming saw the worst outbreak of the disease in a decade, with a case rate far exceeding the national average and four human deaths.

The year before, only three cases in total had been reported.

The WDH warned earlier this year that the conditions could lead to another season of above average WNV cases.