More than 85 monkeypox cases have been identified in 11 countries across Europe, North America, and Australia, an unusual occurrence for a virus that is mostly found in central and western Africa.
On Wednesday, the United States reported its first monkeypox case of the year: a man in Massachusetts.
The health department of New York City announced on Thursday that it is also looking into a probable case.
France, Germany, Sweden, and the Netherlands each confirmed one recent instance as of Friday, while Belgium and Canada reported two and Italy three.
The United Kingdom now has 20, Portugal has 23, and Spain has 30 cases.
One case was recorded in Australia on Friday, in a traveler who had recently returned from the United Kingdom.
More suspected cases are pending confirmation in the majority of those nations.