Ohio health officials are reporting the first human West Nile virus cases of 2015 in Cuyahoga and Hamilton Counties. The case details show a 34- year-old Cuyahoga County man with fever, and more serious, a 77-year-old Hamilton County man with encephalitis.

Culex tarsalis mosquito/CDC
Culex tarsalis mosquito/CDC

“Ohio’s wet summer has caused standing water in many areas of Ohio, and mosquitoes breed and multiply in such water,” said ODH Medical Director Dr. Mary DiOrio. “Ohioans should take reasonable precautions to avoid mosquito bites and eliminate potential mosquito breeding sites.”

The primary way people get West Nile virus is through the bite of an infected mosquito. Most people who become infected with West Nile virus do not have any symptoms. About one in five people who become infected develop a fever with other symptoms such as headache, body aches, joint pains, vomiting, diarrhea, or rash. Less than 1 percent of infected people develop a serious neurologic illness, such as encephalitis or meningitis (inflammation of the brain or surrounding tissues).

Ohio reported 11 human cases of West Nile virus in 2014.

Nationally in 2015, 38 cases and one fatality have been reported to the Centers for Disease Control and Prevention as of July 28. However, this number does not include the most recent cases including the two Ohio cases.