The first case of West Nile Virus reported this season, after a man in the 1960s was hospitalized.
The Massachusetts Department of Public Health said the affected man lives in Middlesex County.
"We haven't seen much West Nile virus activity this year," said Public Health Commissioner Monica Bharel. "Today's news is still a convincing reminder that we all need to continue to take steps to protect ourselves and our families from mosquito bites."
The risk of West Nile virus infection in humans is still low in the state, she said.
The virus is spread through mosquito bites. Most people infected with the virus have no symptoms and some may experience fever and flu-like symptoms. In rare cases, it can cause a more serious illness and people over 50 are at a higher risk of becoming seriously ill, she said.
This year, the bigger problem has been Eastern Equine Encephalitis, which is also spread by mosquitoes and can cause much more serious illnesses and can be fatal. This year, seven cases have been reported in Massachusetts, including a 5-year-old girl in Sudbury and a 60-year-old in Northborough.
"While Massachusetts sees a very active season for another mosquito-borne disease, Eastern Equine Encephalitis, this is the first human case of (West Nile Virus)," said state epidemiologist Dr. Catherine Brown. "We strongly recommend personal precautions to reduce the risk of any mosquito-borne disease."
On August 29, a horse in Granby was also infected with the EEE virus. The department has now confirmed that this horse was stable in Connecticut. As a result, the cities of Granby, Belchertown, Ludlow, Chicopee, South Hadley have all been reduced to moderate risk.
Other communities including Framingham, Marlborough, Northborough and Sudbury are listed as having a critical risk and Berlin, Boylston, Hudson, Maynard, Stow and Wayland are considered high risk.
Officials advise people to avoid being outside dusk until dawn because they are high bite time for many mosquitoes.
Several high schools have rescheduled night football matches and other sporting events because of the risk and the spraying has occurred in some communities with a critical risk.
People are also recommended to use mosquito repellent with DEET and to wear long pants, long sleeves and socks when traveling outdoors, especially at dusk.
Residents are also urged to drain any standing water to prevent mosquitoes from breeding. They should also repair all screens to keep mosquitoes at home.