Delaware County health officials say they've identified a pool of mosquitoes that are positive for West Nile virus.

Officials warn residents to check their property for any sources of standing water and eliminate them, as they can breed mosquitoes.

They also urge people to wear long-sleeved shirts and long pants to protect against bug bites, and to use insect repellent on exposed skin when outdoors.

Despite this discovery, the county's health department says no human cases have been reported thus far.

While most people infected with West Nile don't develop symptoms, about 1 in 5 develop a fever, along with other symptoms including headaches, body aches, vomiting, diarrhea and rashes.

📸: Getty Images