A rare but deadly disease spread by mosquitoes has one town in Massachusetts closing its parks and fields each evening. Four other towns are urging people to avoid going outdoors at night.

They’re concerned about eastern equine encephalitis. State health officials announced last week a man in his 80s had caught the disease, the first human case found in Massachusetts since 2020.

The town of Plymouth, about 40 miles (64 kilometers) southeast of Boston, announced Friday that it’s closing public outdoor recreation facilities from dusk until dawn each day after a horse in the town was infected with the disease.

There are no vaccines or treatment for EEE.