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 2021 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 (8 out of 10) 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.

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:

  • If possible, avoid outdoor activities between dusk and dawn when mosquitoes are most active and feeding. If you must be outside at dawn or dusk, take precautions such as wearing long sleeves, pants, and loose-fitting clothing.
  • Use insect repellent containing an EPA-registered active ingredients, such as DEET or Picaridin (Follow manufacturers’ instructions on the label) when outside. In addition, certain products containing permethrin are recommended for use on clothing, shoes, bed nets, and camping gear.
  • Insect-proof your home by making sure you have good screens on your windows and doors to keep mosquitoes out.
  • Get rid of mosquito breeding sites by draining standing water from flowerpots, buckets, barrels, pool covers, and wading pools.
  • Avoid over-irrigating your lawns, gardens, or 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.
  • Get your horses vaccinated against West Nile.

WNV 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: 

Ashley Anderson 
Katrina Williams