The World Health Organization does not believe the monkeypox outbreak outside of Africa will lead to a pandemic, an official said on Monday, adding that it remains unclear whether infected people who are not displaying symptoms can transmit the disease.

More than 300 suspected and confirmed cases of monkeypox, a usually mild illness that spreads through close contact, causing flu-like symptoms and a distinctive rash, have been reported in May.

Most cases have been in Europe rather than in the Central and West African countries where the virus is endemic. No deaths have been reported so far.