LONDON—Scientists who have monitored numerous outbreaks of monkeypox in Africa say they are baffled by the disease’s recent spread in Europe and North America.
Cases of the smallpox-related disease have previously been seen only among people with links to central and West Africa. But in the past week, Britain, Spain, Portugal, Italy, United States, Sweden, and Canada all reported infections, mostly in young men who hadn’t previously traveled to Africa.
