Apparently 2 people have died from Eastern equine encephalitis in Massachusetts:

A rare mosquito-borne disease killed a young girl and an elderly man who lived in neighboring towns, health officials said Tuesday as they urged people to protect themselves against the insects.

The two became ill with the dangerous Eastern equine encephalitis virus, known as EEE, within days of a third woman who also lives nearby. She remains hospitalized in serious condition, officials said.

Four New Hampshire residents have also turned up ill with the virus in recent weeks; none have died.

It wasn't clear how or when the disease was contracted by the 5-year-old girl and the 83-year-old man, who lived in the state's southeastern arm, said Dr. Al DeMaria, state director of communicable disease control.

He released few other details and declined to identify the two by name, citing privacy concerns. "Obviously this is a horrendous situation for these families," he said.

A CDC fact sheet on the disease can be found here.