The first known case in the United States of a more severe strain of the monkeypox virus was confirmed in California Saturday.

The monkeypox is caused by a virus transmitted to humans by infected animals and it can also be passed from human to human through close physical contact

The patient was traveling from East Africa, where the mpox disease is endemic. The CDC says the strain does not present a high risk to the general population.

The first case in the U.S. of a more severe strain of monkeypox 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.