A sample of mosquitoes in Teton County, Wyoming has detected the presence of West Nile virus.

The Teton County Weed and Pest District said the sample was collected from a trap on West Gros Ventre Butte last Saturday.  Subsequent sampling has detected no additional infected mosquitoes.

The district planned to spray permethrin by truck in that area Friday night.  Weather permitting, the spraying will be conducted between 9 p.m. and 11 p.m.  

The district is encouraging everyone to reduce exposure to mosquitoes by limiting time spent outdoors in during night time hours, by donning long-sleeved shirts and long pants, and by using an effective mosquito repellent when exposed to biting mosquitoes.

The Wyoming Department of Health reported Thursday that four counties in Wyoming have detected West Nile virus infection in mosquitoes.  13 positive samples were reported in Fremont County.    No human, equine or avian cases have been reported.

West Nile Virus infection in humans may take a range of courses from being completely asymptomatic (80% of cases) to a flu-like presentation with fever, headache, muscle aches, fatigue and swollen lymph nodes.  This disease progression (occurring in just under 20% of those infected) is known as West Nile Fever and may also include symptoms such as a skin rash on the trunk or eye pain. 

A fraction of one percent of those infected will develop neurological involvement in the form of encephalitis, meningitis or poliomyelitis. Symptoms of these serious conditions may include disorientation, photophobia, neck stiffness, drowsiness, vomiting, paralysis and coma.

Anyone experiencing any of these symptoms is encouraged to contact their healthcare provider.  A blood test can confirm the disease and offer surveillance information to help stem the spread of the virus in Teton County.

People can also assist in surveillance efforts by reporting dead or diseased birds or adult mosquito populations at (307) 733-1896.