The North Shore Mosquito Abatement District said the batch was collected on Monday in a trap and tested positive for the virus on Thursday.

Illinois has confirmed its first human case of West Nile virus this year, health officials say. The person, who lives in southern Illinois, was hospitalized with complications from the mosquito-borne virus.

The first human case of West Nile virus in Illinois has been confirmed by the U.S. Centers for Disease Control, according to the Illinois Department of Public Health