As monkeypox’s name suggests, the viral disease originated in monkeys. Small outbreaks of monkeypox have been detected in humans in the past, though mostly in Central and West Africa where the infection originated. That is why an unprecedented wave of infections in cities across Europe and North America has caught researchers by surprise and is concerning public health officials.
As of May 21, 92 confirmed new cases of monkeypox and 28 suspected cases have been detected in 12 countries in which the virus does not usually circulate, according to the World Health Organization. The number of cases recorded in the past week is higher than the total number of cases that had been recorded in those non-endemic regions since records began in 1970, and more are appearing each day.
Monkeypox infections in Europe and the U.S. are usually isolated cases where someone has traveled from Africa or come into contact with an exotic animal. Most of these recent cases have been found in Europe, with the first infection identified in a traveler returning to the U.K. from Nigeria. As of this week, 19 confirmed and suspected cases had been found in England, 33 in Portugal and 51 in Spain, according to a database compiled by Moritz Kraemer and colleagues at The University of Oxford.