PEORIA — The West Nile virus has been found in mosquitoes in Peoria County, the Peoria City/County Health Department reported Tuesday.

West Nile is transmitted through bites from infected mosquitoes. Symptoms, which include fever, nausea, headache and muscle aches, may last from a few days to a few weeks. Four out of five people infected with West Nile virus will not show any symptoms, but, in rare cases, severe illness including meningitis or encephalitis, or even death, can occur.

People older than 50 are at higher risk for severe illness from West Nile virus.

“The best way to prevent West Nile disease or any other mosquito-borne illness is to reduce the number of mosquitoes around your home and to take personal precautions to avoid mosquito bites,” said Carey Panier, PCCHD Interim Director of Environmental Health.

Panier suggests people practice the three Rs to prevent disease — reduce exposure by staying inside when mosquitoes are most active between dusk and dawn, repel mosquitoes by wearing protective clothing and insect repellent, and report mosquito breeding grounds, such as stagnant water in roadside ditches.