A Johnson County resident older than age 65 has died of West Nile virus, said Barbara Mitchell, spokeswoman for the county’s health department.

The state now has four reported human cases this year. In Reno County, a 72-year-old resident and a 57-year-old resident are hospitalized, the Kansas Department of Health and Environment said Friday. A Harvey County child, who was not hospitalized, was the first confirmed case this year.

KDHE spokeswoman Sharon Watson said the state saw a peak of the virus in 2003 with 90 human cases and seven deaths. The state had 46 human cases and two deaths in 2004 and 25 human cases with one death last year.

“We believe that many people have had it and don’t realize it because symptoms don’t show up or are very mild, and they become immune to it. It’s likely that many Kansans are immune to it,” she said.

According to KDHE, human cases are more common later in the summer. The agency advises people to use insect repellent with DEET, limit activities at dawn and dusk, and remove standing water.