Dr. Heymann told The Associated Press during an interview that the leading theory for the outbreak has been linked to sexual transmission among gay and bisexual men at two raves held in Spain and Belgium. Heymann stated, “We know monkeypox can spread when there is close contact with the lesions of someone who is infected, and it looks like sexual contact has now amplified that transmission.”

More than 90 cases have been reported in the U.S., Britain, Spain, Israel, France, Switzerland, and Australia. In Spain, where a Gay Pride event was held in the Canary Islands and drew some 80,000 people, there have been 30 cases confirmed. Cases previously hadn’t been recorded outside of central and western Africa, where people are infected by animals like wild rodents and primates.

Source: NBC News