Michigan health official say the travelers were from Midland and Wexford counties.
Last year, 36 people got sick and two died from West Nile Virus,
Michigan has its first confirmed human case of West Nile Virus infection, a year after at least 17 people died and 202 came down with the mosquito-borne disease in the state.
Texas researchers have found a link between a warmer winter and higher infection rates the following summer.
So far, the turkey is the first animal in the state to test positive this year for the disease.
A fifth death associated with the mosquito-borne West Nile virus has been reported in Michigan.
With more Michiganders spending time outside for the extended Labor Day weekend, the Michigan Department of Community Health is reminding residents of the simple precautions that can be taken to avoid mosquito bites during the holiday this year.
After a third West Nile death in Michigan has been confirmed, WWJ Newsradio 950 is hosting a special webinar at noon Friday, Aug. 24 with local doctors who will answer your questions about the illness.
A second person in Michigan has now died from the West Nile virus, and 18 more cases have been reported this week.
City departments in Warren will begin a mosquito prevention and eradication program aimed at controlling the spread of the West Nile virus and other illnesses.