Two cases of neuroinvasive West Nile virus confirmed in Johnson County residents, says KDHE

Mosquitos in the Culex family are known vectors of West Nile virus. Photo credit Andy Murray. Used under a Creative Commons license.

The Kansas Department of Health and Environment announced on Tuesday that it had confirmed cases of neuroinvasive West Nile virus in two individuals who reside in Johnson County.

They are the first confirmed cases of human West Nile virus in the state this year. Much of Kansas remains under a high-risk warning for West Nile virus. Northeast Kansas, which includes Johnson County, and southeast Kansas are under a moderate warning.

Neuroinvasive West Nile virus is the most severe form of the infection, and leads to swelling of the brain. In the most serious cases, it can cause death. According to KDHE, about one in 150 people infected with West Nile Virus develop a neuroinvasive infection.

“Although for most people West Nile virus may not cause a great deal of concern, we encourage residents, especially our vulnerable populations, to take steps to prevent infection because of the potential for complications,” said Dr. Greg Lakin, KDHE Chief Medical Officer.

The virus, which is spread by mosquito bites, leads to a symptomatic infection, which usually manifests with a fever, headache or rash, among other symptoms, in about one in five people. Late summer and early fall are the most likely times for West Nile virus infections. KDHE offered the following tips on preventing infection:

  • When you are outdoors, use insect repellent containing an EPA-registered active ingredient on skin and clothing, including DEET, picaridin, oil of lemon eucalyptus, or IR3535. Follow the directions on the package.
  • Many mosquitoes are most active at dusk and dawn. Be sure to use insect repellent and wear long sleeves and pants at these times or consider staying indoors during these hours.
  • The elderly or those with a weakened immune system should consider limiting their exposure outside during dusk and dawn when the Culex species mosquitos are most active.
  • Make sure you have good screens on your windows and doors to keep mosquitoes out.
  • Get rid of mosquito breeding sites by emptying standing water from flower pots, buckets and barrels. Change the water in pet dishes and replace the water in bird baths weekly.
  • Drill holes in tire swings so water drains out. Keep children’s wading pools empty and on their sides when they aren’t being used.

Since 1999, there have been 30 deaths in Kansas attributed to West Nile virus.

“Symptoms of WNV disease include fever, headache, weakness, muscle pain, arthritis-like pain, gastrointestinal symptoms, and rash typically developing two to 14 days after a bite from an infected mosquito,” said KDHE in the announcement. “People who are concerned about symptoms should speak with their physicians.”