NEW YORK (PIX11) — The New York City Department of Health is investigating a possible case of monkeypox within the city. The smallpox-like illness was confirmed to be in Massachusetts on Tuesday.

The possible monkeypox patient is being treated at NYC Health + Hospitals/Bellevue. Isolation protocols are being followed, according to the Department of health. If positive, tests will be sent to the Centers for Disease Control and Prevention.

Monkeypox is uncommon in the U.S. It usually presents as a flu-like illness accompanied by swelling and a rash on the face and body. In 2003, 47 people in six U.S. states had confirmed or probable cases. They caught the virus from pet prairie dogs that been housed near imported small mammals from Ghana.

“We don’t expect to see a lot of cases,” Dr. Anthony Santella, who works in health sciences at the University of New Haven, told PIX11 News. “It’s not like people who rode the subway or were in a public place need to panic.”

The virus originates in wild animals like rodents and primates, and occasionally jumps to people. Most human cases have been in central and west Africa, where the disease is endemic.

Monkeypox can be fatal for up to one in 10 people and is thought to be more severe in children.

People exposed to the virus are often given one of several smallpox vaccines, which have been shown to be effective against monkeypox. Anti-viral drugs are also being developed.

“I know it sounds very alarming to hear about an illness that most people have never heard of,” Santella added, “but monkeypox is extremely rare.”