More than 250 cases of monkeypox have been confirmed around the world over a two-week period, but a pandemic is unlikely, a World Health Organization expert said Monday.

Ten cases were confirmed in the U.S. from May 13 to May 26, the WHO said. The U.S. is one of 23 countries outside endemic regions for monkeypox to report cases over the time period – a total of 257 confirmed cases and an additional 117 to 127 suspected cases that were still being investigated. 

No deaths have been reported.

“At the moment, we are not concerned about a global pandemic,” said Dr. Rosamund Lewis, technical lead on monkeypox for the WHO. “We are concerned that individuals may acquire this infection through high-risk exposure if they don’t have the information they need to protect themselves.”

Lewis said the vast majority of cases being seen in dozens of countries globally are in gay or bisexual men. But she warned that anyone is at potential risk of the disease, regardless of their sexual orientation.

Monkeypox virus is transmitted from one person to another by close contact with lesions, body fluids, respiratory droplets and contaminated materials such as bedding. The incubation period of monkeypox is usually from six to 13 days but can range from five to 21 days, the WHO says.

“The situation is evolving rapidly and WHO expects that there will be more cases identified as surveillance expands in non-endemic countries,” the WHO warned in an updated released Sunday.

MONKEYPOX NOW IN 7 STATES: US health officials urge awareness, not fear.

Early symptoms of monkeypox can include fever, muscle aches, chills and fatigue. In more severe cases, a rash can develop, often on the face and genitals. There are two antivirals being used to combat the infection, but most people with the infection suffer only mild symptoms that don’t require the drugs.