The first case in the U.S. of a more severe strain of monkeypox was reported in San Mateo County, the Centers for Disease Control and Prevention said.
Testing confirmed the monkeypox case was the clade I strain, and according to the California Department of Public Health, the person had recently traveled from Africa, where there is an ongoing outbreak.
The CDPH said the person who tested positive received treatment and is isolating at home. Anyone who was in contact with them is being contacted by public health officials.
No other cases have been reported.
The clade I strain has historically caused more severe symptoms than clade II. The Centers for Disease Control and Prevention said risk to the general public is low.