(Cheyenne, Wyo.) – The number of West Nile virus (WNV) cases reported to the Wyoming Department of Health (WDH) this year has grown to 13, including a Park County man who died.

“We have definitely seen an uptick in WNV cases in Wyoming over the last few weeks,” said Emily Thorp, WDH surveillance epidemiologist. “South Dakota, a neighboring state, is experiencing a particularly active WNV season and WNV reports have recently gone up across the country.”

Ten confirmed cases have been reported so far from Fremont County, one each from Platte and Natrona counties, and one fatal case from Park County.  WDH is following up on additional potential cases.

In the latest mosquito monitoring effort, only a trap in Hudson recorded WNV carrying Culex mosquitos. Of the 60 mosquitos trapped on Ohio Street in Hudson, 44 were of the Culex variety, the mosquito species known to carry the virus. In the lastest count from Lander, only a few mosquitos were trapped, three were Culex and none tested positive for WNV. Just three locations in the county were trapped this week.

In Wyoming last year, seven human WNV cases were reported with no deaths. Since WNV first appeared in Wyoming in 2002, the annual numbers of reported human cases have ranged from two with no deaths to 393 and nine deaths.

Because WNV transmission is still possible into Wyoming’s fall months, Thorp suggested people continue to take precautions:

1) DAWN and 2) DUSK – Most mosquito species 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 or when mosquitoes are most active. Clothing should be light-colored 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 it.

5) DEET – Use an insect repellent containing DEET (N, N-diethyl-m-toluamide). When using DEET, be sure to read and follow the label instructions. Other insect repellents such as Picaridin (KBR 3023) or oil of lemon eucalyptus can also be effective.

According to the WDH, most people infected with WNV never develop symptoms.  Among those who become ill, symptoms include fever, headache, body aches, skin rash and swollen lymph nodes.  A very small percentage of infected persons develop West Nile neuroinvasive disease (i.e. meningitis or encephalitis) with symptoms such as severe headache, fever, neck stiffness, stupor, disorientation, coma, tremors, convulsions and paralysis.

–Wyoming Department of Health