Medical and public health officials are concerned—and puzzled—by the increasing number of confirmed monkeypox cases in countries outside central and western Africa, where the virus is endemic.
In the past 5 years, scientists have confirmed only 8 cases where travelers carried monkeypox to countries outside Africa, including 2 cases last year in the US. Each was linked to a person who had recently spent time in Nigeria, a country that experienced a resurgence in monkeypox starting in 2017. In those cases, the human-to-human spread was limited; 2 family members became infected in one instance, according to the World Health Organization (WHO). One health care worker who had contact with contaminated bedsheets was infected in another case, report experts in an article published in the CDC’s Emerging Infectious Diseases.