Public health officials in Massachusetts on Friday reported an 11th person in the state has been diagnosed with West Nile virus this year.

The Massachusetts Department of Public Health said the latest case involves a man in his 60s who recently traveled out of state.

“Although the person’s recent travel outside of Massachusetts means the exact location of exposure is uncertain, there is a possibility he could have been exposed within the Greater Boston area, which is already known to be at high risk,” a statement from the department said.

DPH said it is raising the eastern equine encephalitis risk levels to high in Concord in Middlesex County due to two consecutive weeks of EEE-positive mosquito findings in species known to be able to spread the disease to people. Officials said it is an expansion of an area already considered to be at high risk from EEE.

“It may be mid-September, but warm and humid weather continues across Massachusetts, keeping the risk of both EEE and West Nile elevated,” said Public Health Commissioner Robbie Goldstein. “There will continue to be risk from mosquito-borne disease until the first hard frost, and I encourage everyone to continue to take measures to protect themselves.”

The DPH said 314 mosquito samples have tested positive for West Nile this year.

There have been 95 EEE-positive mosquito samples, four human cases and two horse cases reported in Massachusetts so far this year, DPH said.