Eastern equine encephalitis detected in Massachusetts and Michigan

Health officials in Massachusetts and Michigan have reported recent activity of Eastern equine encephalitis (EEE), a rare and potentially fatal mosquito-borne virus.

In Massachusetts, the Department of Public Health confirmed the presence of the virus in mosquito samples collected on August 17 in Kingston, Plymouth County. While no human or animal cases have been reported in the state this year, the finding has raised the risk level to moderate for the communities of Carver, Halifax, Kingston, and Plympton. Officials noted that while the detection comes late in the season, residents should use repellent to prevent bites.

In Michigan, the state health department confirmed the first locally acquired human case of EEE since 2021. The patient is a resident of Roscommon County. Michigan’s Chief Medical Executive, Natasha Bagdasarian, noted that the disease has a 30% fatality rate among those who become ill. Health authorities are conducting additional mosquito trapping and testing in Roscommon County to assess local risk levels.