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.

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.

Health officials said Saturday they have confirmed the first U.S. case of a new form of mpox that was first seen in eastern Congo. The person had traveled to eastern Africa and was treated in Northern California upon return, according to the California Department of Public Health. Symptoms are improving and the risk to the public is low.