Over the weekend California reported the first known clade 1 mpox case in the United States, which involves someone who recently returned from an affected African country and sought care in San Mateo County.

Health officials from the California Department of Public Health (CDPH) have not confirmed if the infection is cause by clade 1b, a more transmissible and severe mpox virus causing a widespread outbreak that started in the Democratic Republic of the Congo (DRC).