The person had traveled to eastern Africa and was treated in Northern California upon return, according to the California Department of Public Health.

There is no evidence that the mpox clade I strain is spreading between people in California or elsewhere in the U.S.

A person in California has tested positive for a form of mpox causing a widespread epidemic in Africa, the state’s Department of Public Health reported on Saturday. It is the first known case in the United States.

A new strain of mpox has been confirmed on American shores after a traveler returned to California from a visit to Africa, but risk to the public remains "very low."

The first case in the U.S. of a more severe strain of mpox was reported in San Mateo County, the California Department of Public Health said.

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 United States’ first known case of a more severe strain of mpox was confirmed in California, the US Centers for Disease Control and Prevention said Saturday. The risk of clade I mpox to the public remains low,