A third person has died of Eastern equine encephalitis in Massachusetts, raising the reported death toll from the rare mosquito-borne illness to six nationwide, CNN reports.

The victim is among the 10 confirmed human cases of the illness previously reported in Massachusetts, the state's Department of Public Health said Monday.

Eastern equine encephalitis (EEE) is a rare but potentially fatal illness caused by mosquito bites. Typically, five to 10 human cases are reported every year, with about 30% of all cases resulting in death, according to the US Centers for Disease Control and Prevention.

"We continue to emphasize the need for people to protect themselves from mosquito bites," Massachusetts Public Health Commissioner Monica Bharel said in a news release last week. "It is absolutely essential that people take steps to avoid being bitten by a mosquito."

Bharel's comments came Friday as the state announced that a man in his 70s from Bristol County had become the second person to die after contracting the illness. His death followed that of Laurie Sylvia. She died in late August after being treated at Tufts Medical Center in Boston, said Jeremy Lechan, a spokesman for the medical center.

Cases of the illness have also been reported in nearby states.