BOSTON – Though the risk of West Nile virus is decreasing with the temperature, state officials Thursday announced this year’s eighth human case of the virus and said that 98 cities and towns remain at high or moderate risk.

The Department of Public Health said a man in his 50s who was exposed to the mosquito-borne disease in Middlesex County was confirmed to be infected with the virus, making him the eighth person in the Bay State to get West Nile virus this year.

“The risk from WNV is starting to decline but some risk will remain until the first hard frost,” Acting Public Health Commissioner Margret Cooke said. “Although people over the age of 50 are at greater risk from West Nile virus, all ages can be affected. People should remember to take steps to prevent mosquito bites anytime they are outdoors.”

DPH officials said people across Massachusetts should use mosquito repellents with an EPA-registered active ingredient, wear long sleeves and long pants when outdoors to reduce exposed skin, and stay aware of mosquito activity in the community.

The 27 communities at high risk for West Nile virus are in Essex, Middlesex, Norfolk, and Suffolk counties, DPH said, while 71 other communities around the state are at moderate risk on the state’s West Nile virus risk map.

In 2019, Massachusetts reported five cases of West Nile virus. Last year, DPH publicly announced eight human cases of WNV but said last month that the real total was 11 human cases in 2020.

When it announced the first human case of 2021 on Sept. 1, DPH said that the risk from West Nile virus had been “slow to increase this year” but then went on to confirm six more human cases last month.