There have been four batches of mosquitoes that have tested positive for West Nile virus in Grundy County this year and, although Grundy has never had any reported human cases, people should still take precautions.

"People who develop any of the West Nile illnesses can be very seriously harmed. So a little precaution does go a long way," said Michael Boyle, environmental health director for the  Grundy County Health Department.

West Nile is a virus that can be transmitted to humans through mosquito bites.