WAUKEGAN, Ill. (AP) — Tests on mosquitoes have revealed for the first time this year the presence of the West Nile virus in Lake County in Northern Illinois.

The county's health department says the tests were done on mosquitoes collected June 28 in Highland Park. The tests come about a month after officials announced the state's first mosquitoes to test positive for the virus were found in two Cook County suburbs.

There have been no reports of people contracting the virus this year in Lake County. Last year, 104 batches of mosquitoes and one bird tested positive. Since 2002, there have been 64 confirmed cases in humans in the county — two of which were fatal.

Most people infected with the virus show no symptoms of illness but some develop symptoms such as high fever and nausea.