Half of Kansas listed as "high risk" next week for West Nile

TOPEKA – The Kansas Department of Health and Environment issued a high-risk warning for West Nile virus infections Friday for about half the state, including southcentral and southwest Kansas.

No positive case of West Nile transmission have been confirmed yet this year, but a combination of weather conditions, an increase in the number of mosquitoes in the species that carries the virus, and historical data on human cases during this week over the past five years resulted in the warning.

The state’s latest count of Culex mosquitoes, as well as an increase in the two-week average temperature for the region, resulted in a moderate risk assessment for both southwest and south central, according to a report on the Kansas Department of Health and Environment website.

When combined with the historic number of human cases of West Nile for next week’s dates, based on a five-year average, that pushed the state’s warning in this region to high.

North Central Kansas also is listed in the high-risk category, with northeast, southeast, and northwest Kansas all at moderate risk for WNV infections.

Although there have been no cases of WNV reported to KDHE in 2018 – most infections occur in the late summer and early fall – there have been more than 600 cases of the most severe form of WNV and 30 deaths in Kansas since the virus first showed up here in 1999, the KDHE advised.

West Nile virus is spread to people through mosquito bites, but it cannot spread from person to person. About one in five people who are infected develop a fever and other symptoms. About one in every 150 infected people develop swelling of the brain or brain tissue that in some cases can result in death.

There are no vaccines or medications to treat WNV in humans, though people who have had WNV before are considered immune. There is a vaccine for horses, which can also be killed by the virus.

“Know your risk and take action to prevent mosquito bites to protect yourself and your family against West Nile virus,” State Health Officer Dr. Greg Lakin stated in a release.