LEXINGTON, Ky. — The Lexington-Fayette County Health Department confirmed its fourth case of West Nile Virus on Wednesday, according to a press release from the department, marking a sharp increase in mosquito-borne illnesses across Kentucky this season.

The announcement came after the Kentucky Department for Public Health issued a statewide health alert on September 30 regarding rising cases of West Nile Virus and La Crosse virus. All four Lexington cases have required hospitalization, with victims ranging from 30 to 77 years old. The infected residents either lived in or spent significant time outdoors in the 40502, 40505 and 40509 zip codes, according to the health department.

The statewide numbers highlight an unprecedented surge: Kentucky has recorded 19 West Nile cases statewide, including one death, compared to an average of seven cases annually. The death occurred in a resident from Daviess County. Beyond West Nile, the state confirmed two cases of La Crosse virus with two additional suspected cases under investigation in Eastern and Central Kentucky, compared to only 11 total La Crosse cases reported statewide from 2003 to 2024.

The surge extends beyond Lexington. Louisville Metro health officials reported nine confirmed West Nile cases, with seven requiring hospitalization, all involving adults between ages 40 and 70.

West Nile Virus is transmitted when an infected mosquito bites a human or animal. Symptoms typically develop three to 14 days after infection and include fever, headache, body aches, nausea, vomiting, swollen lymph glands, neck stiffness, tremors, vision loss, muscle weakness or rash. Milder cases improve without medical intervention, though those experiencing severe headaches or confusion should seek immediate attention.

The Lexington-Fayette County Health Department has intensified mosquito control efforts, conducting weekly trapping at six locations to monitor populations. Spraying operations target areas with elevated mosquito activity, using a pesticide called Duet applied at low doses. The health department has already sprayed affected neighborhoods in the three zip codes where cases were identified.

Residents can reduce infection risk by using EPA-labeled insect repellents containing DEET, Picaridin or oil of lemon eucalyptus, particularly during peak mosquito hours from dusk to dawn. Wearing long sleeves, long pants and socks during outdoor activities also provides protection. To eliminate breeding grounds, residents should remove standing water from tires, gutters, flower pots, birdbaths, buckets and pet dishes. To report standing water or excessive mosquito problems, residents can contact the department's Environmental Health and Protection division at (859) 231-9791.