First human case of West Nile virus of the year confirmed in Mass.

The first human case of West Nile virus this year has been confirmed in Massachusetts, health officials said.

The Massachusetts Department of Health announced Thursday that a man in his 90s was exposed to the virus in Middlesex County. The announcement comes one day after two mosquitoes tested positive for Eastern equine encephalitis virus in Plymouth County.

Additionally, the risk of West Nile virus was elevated to a moderate level in 70 communities across Barnstable, Berkshire, Bristol, Essex, Franklin, Hampden, Hampshire, Middlesex, Norfolk, Plymouth, and Worcester counties, the department said.

The first mosquito that tested positive for West Nile virus in the state was detected on June 16. Since then, 180 mosquitoes with the virus have been detected across Barnstable, Berkshire, Bristol, Dukes, Essex, Franklin, Hampden, Hampshire, Middlesex, Norfolk, Plymouth, Suffolk, and Worcester counties, the department said.

“West Nile virus can be a [devastating] disease, especially for those who are older or have compromised immune systems. This first case in Massachusetts should remind people across the state that risk remains high,” said Public Health Commissioner Robbie Goldstein. “While most people exposed to WNV will not develop serious illness, some may develop very severe illness requiring hospitalization. In some cases, the disease can be fatal.”

“People should use mosquito repellent with an EPA-registered active ingredient, clothing to reduce exposed skin, and consider rescheduling outdoor activities that occur during the evening or early morning when mosquitoes are most active,” until the first hard frost, said State Epidemiologist Dr. Catherine M. Brown.

To prevent contracting West Nile virus, wear insect repellent when outdoors, especially from dusk to dawn, and wear long clothing, the department said. At home, drain standing water where mosquitoes could lay eggs and install or repair window and door screens.

The state maintains an online map of where the risk of West Nile virus is highest in the state.