According to CDC and local health authorities, 11 cases of eastern equine encephalitis (EEE; including 1 death) have occurred since July 2024 in the states of Massachusetts, New Hampshire, New Jersey, New York, Rhode Island, Vermont, and Wisconsin. Eastern equine encephalitis is caused by a virus spread to people through the bite of an infected mosquito.
Although rare, eastern equine encephalitis is very serious. Approximately 30% of people who develop severe eastern equine encephalitis die, and many survivors have ongoing neurologic problems. There are no vaccines to prevent or medicines to treat eastern equine encephalitis.
People living in areas where eastern equine encephalitis virus circulates should protect themselves by preventing mosquito bites. The general risk to travelers is minimal. The mosquito species implicated in EEE transmission to humans generally have peak activity ranging from late afternoon through dusk and again from dawn through early morning.
