Sample tests positive for West Nile Virus in Cascade County

The Cascade County Weed and Mosquito Division has detected its first West Nile Virus positive mosquito sample this year.

A WNV positive sample of adult Culex tarsalis mosquitos was collected approximately 6 miles north of Great Falls on July 12. The sample was confirmed to be West Nile Virus positive by the lab at the Montana Department of Public Health and Human Services in Helena on July 16.

County doubling down on mosquito control after flooding

Last summer, three samples tested positive for WNV.

Third sample tests positive for West Nile Virus in Cascade County

There has been no known infection in humans detected in Cascade County so far this year, but since a WNV positive mosquito sample has been detected, the Cascade City-County Health Department is encouraging residents to take steps to protect themselves.

The severity and symptoms of WNV can vary widely. Approximately 80 percent of people infected experience no symptoms, but up to 20 percent of people can develop a mild illness, called West Nile fever, according to CCHD. Fever generally resolves itself without treatment, but dangerous brain infections such as encephalitis or meningitis can develop in 1 out of 150 people. Symptoms of these diseases might include headache, rash, high fever, stiff neck, mental confusion, muscle weakness, tremors, convulsions, coma, and paralysis. Individuals who develop any of these symptoms should see their healthcare provider immediately.

The single best defense against WNV is bite prevention. To protect yourself, CCHD recommends using the 5 Ds:

  • DEET-Apply repellent containing an EPA-registered active ingredient, such as DEET, and follow the directions on the package.
  • DUSK and DAWN-This is when mosquitoes are most active. Try to avoid outdoor activities during these times.
  • DRAIN STANDING WATER-Standing water is the perfect breeding ground for mosquitoes. Drain such areas around your home (gutters, pools, tires, buckets, water bowls, etc.).
  • DRESS APPROPRIATELY-Wear long-sleeved shirts, long pants, and socks.

Last month, the Cascade County Commission approved an additional $45,000 for the Mosquito Control Fund to purchase additional chemicals and retreat areas that were impacted by the flooding.