Human West Nile Virus Case Identified in Canyon County Health Officials Encourage Taking Precautions


Human West Nile Virus Case Identified in Canyon County
Health Officials Encourage Taking Precautions

CALDWELL, IDAHO – West Nile virus has been confirmed in a Canyon County resident. This is the first 2022 human case of West Nile virus (WNV) infection in the counties served by Southwest District Health.

West Nile virus (WNV) is a potentially serious illness that is usually spread to animals and humans through the bite of an infected mosquito. It does not spread from person-to-person. Most people infected with the virus do not show symptoms, although more severe symptoms may occur, especially in individuals older than 60. People with symptoms may experience fever, headaches, body aches, fatigue, nausea, vomiting, and sometimes swollen lymph glands or a skin rash typically occurring 2 to 14 days after the bite of an infected mosquito.

“About one in 150 people infected with WNV develop severe illness such as encephalitis (inflammation of the brain), or meningitis (inflammation of the linings of the brain and spinal cord),” said Ricky Bowman, Program Manager for Southwest District Health. “These more severe infections are marked by a rapid onset of a high fever, headache, neck stiffness, body aches, disorientation, and tremors, and may require hospitalization” he said.

Measures to lessen the chance of bites from infected mosquitos are underway in Canyon County. “Surveillance and control measures throughout the county have already been increased in response to several previous West Nile virus positive mosquito samples,“ said Jim Lunders, Director of Canyon County Mosquito Abatement District.

The more time you spend outdoors, the higher your chances are that you could be bitten by an infected mosquito. To reduce your risk of contracting WNV you should:

  • Avoid outdoor activities between dawn and dusk when mosquitoes are most active and feeding
  • Wear long sleeves, pants, and loose-fitting clothing if you must be outside between dawn and dusk
  • Use insect repellent containing DEET, Oil of Lemon Eucalyptus, IR3535 or Picaridin (follow manufacturers’ instructions) when outside. In addition, certain products containing permethrin are recommended for use on clothing, shoes, bed nets, and camping gear.
  • Remove mosquito breeding sites by draining standing water from flowerpots, buckets, barrels, pool covers, and wading pools. Water held for seven days can produce mosquitoes.
  • Avoid over irrigating your lawns, gardens, and pastures
  • Change the water in pet dishes and replace the water in bird baths and watering troughs at least twice weekly.
  • Drill holes in tire swings or old tires so water drains out.
  • Vaccinate your horses against West Nile virus.
  • Notify the District at 208-461-8633 if you have a site that is too large to be eliminated so it can be properly treated.

West Nile virus does not usually affect domestic animals, such as dogs and cats, but it can cause severe illness in horses and certain bird species. There is no human vaccine available but there are vaccines available for horses. People are advised to vaccinate their horses to protect them against WNV.

For more information on WNV please visit:

For more information on insect repellents, please visit:

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Media Contacts

Southwest District Health:

Ashley Anderson

Katrina Williams

Canyon County Mosquito Abatement District:

Jim Lunders