The West Nile virus has been found in mosquitoes in Sedgwick County, the Kansas Department of Health and Environment announced Friday.
Mosquitoes in Reno, Shawnee and Johnson counties also tested positive for the virus, officials said.
West Nile can be spread to people through bites from infected mosquitoes, but it is not contagious from person to person, the KDHE reported. Symptoms range from a slight headache and low-grade fever to swelling of the brain or brain tissue. In rare cases, West Nile can be fatal.
People who have had West Nile before are considered immune.