People of any age can become severely ill with West Nile virus, but the risk is highest for people age 50 and over and for organ transplant recipients.

Sharon Watson, spokeswoman for the Kansas Department of Health and Environment, said Tuesday that lab tests have not confirmed the case. However, she said the doctor who treated the resident in mid-May reported West Nile symptoms.

The Centers for Disease Control and Prevention said it was the first human case reported. The disease has appeared in birds, horses and mosquitoes -- the insect that carries West Nile -- in 14 states so far this year.

About 2 out of 10 Have Symptoms

Last year, 2,535 human cases and 98 deaths were reported to CDC, with Western states hit the hardest. The worst year for West Nile virus since its appearance six years ago was 2003, with 9,862 reported cases and 264 deaths.

Over the past six years, it has now been confirmed in every state except Alaska and Hawaii, according to the CDC.

Most people infected show no symptoms at all, but about 2 out of 10 have symptoms that include fever, aches, nausea and vomiting. About 1 in 150 people develop more serious symptoms and some die, according to the CDC. Although people of any age can become severely ill, the risk is highest for people age 50 and over and for organ transplant recipients.