High Risk of West Nile Virus Activity in Three Kansas Regions

and Positive Mosquito Pools Identified

TOPEKA – The Kansas Department of Health and Environment (KDHE) has issued a high risk warning for West Nile virus infections (WNV) for northwest, south central and southeast Kansas. North central, northeast, and southwest Kansas are at moderate risk for WNV infections. In addition, mosquitoes collected in Sedgwick County have tested positive for WNV and St. Louis Encephalitis virus (SLEV).

WNV can be spread to people through mosquito bites, but it is not spread from person to person. About 1 in 5 people who are infected develop a fever and other symptoms such as headache, body aches, joint pains, vomiting, diarrhea, or rash. About 1 out of 150 infected people develop a severe illness leading to swelling of the brain or brain tissue that can result in death. There are no vaccines or medications to treat WNV. People who have had WNV before are considered immune.

SLEV is transmitted by the same type of mosquito that spreads WNV. While most people who are infected with SLEV have no symptoms or only mild non-specific flu-like illness, some individuals can experience serious neuroinvasive illness. Symptoms often include fever, headache, stiff neck, disorientation, and altered level of consciousness. Coma, convulsions, and paralysis may also occur. SLEV has a similar incubation period as WNV, 5-15 days.

KDHE recommends knowing your risk of WNV and take action to prevent mosquito bites and protect yourself against WNV and SLEV:

• Visit the KDHE WNV website weekly to learn about the current WNV risk levels; http://www.kdheks.gov/epi/arboviral_disease.htm
• 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.
• Horses can also be infected with WNV. Talk with your veterinarian about vaccinating your horse to protect them against WNV.

Most WNV infections occur in the late summer and early fall. Although there have been no cases of WNV reported to KDHE in 2019, there have been over 300 cases of the most severe form of WNV and 30 deaths in Kansas from 1999-2018. The last known case of SLEV in Kansas occurred in 2004.

The Centers for Disease Control and Prevention provides this web page with additional information about West Nile virus and preventing mosquito bites: http://www.cdc.gov/features/StopMosquitoes/.  More information on SLEV can be found at https://www.cdc.gov/sle/index.html .For questions about West Nile virus or other Arboviral diseases contact the KDHE Epidemiology hotline at 877-427-7317.