Health officials on Saturday said they have identified the first U.S. case of an mpox strain that has recently prompted global health alerts over concerns about its spread, severity and transmissibility.

The first known case of clade I mpox in the U.S. was recently discovered in a person in California, the Centers for Disease Control and Prevention said Saturday.

The individual is recovering after traveling from Africa, where an outbreak that has killed hundreds is spreading.

California has reported the first US case of mpox - formerly known as monkeypox - that is part of a new outbreak. The state's department of health, the CDPH, said the new case was from the Clade I strain - different from the Clade II strain that has been in circulation in the US since 2022.

Mpox is a rare disease caused by infection with a virus that’s in the same family as the one that causes smallpox. It is endemic in parts of Africa, where people have been infected through bites from rodents or small animals.

The first case of clade I mpox was reported in California, the CDC said. The individual was treated and is now isolating at home.