A person in California tested positive for mpox clade I, the first time the strain has been reported in the U.S.

The United States has confirmed its first known case of clade 1 mpox, a more severe strain of the virus, in California.

United States on Saturday said the first known case of a more severe strain of the monkeypox (Mpox) virus was reported in California. The case involves an individual who recently returned from Eastern Africa.

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.

The first known case in the United States of a more severe strain of the monkeypox virus was confirmed in California Saturday as health officials said an individual who recently returned from Africa contracted the latest form of the disease.