First mpox case linked to African outbreak reported in U.S.

California health officials have confirmed the first U.S. mpox case caused by the Clade I variant linked to the ongoing mpox outbreak in Africa.

The California Department of Public Health (CDPH) announced Saturday that it detected the Clade I mpox variant in an individual with a recent travel history to Africa. The CDC has been notified of the case found through lab testing.

The agency said that the individual is in recovery and isolating at home after receiving medical care in San Mateo County. Healthcare workers are reaching out to the patient’s close contacts.

However, “there is no concern or evidence that mpox Clade I is currently spreading between individuals in California or the United States,” CDPH noted.

In August, the World Health Organization declared the current mpox outbreak, which started in the Democratic Republic of Congo and is linked to the Clade I variant, a global public health emergency.

Clade I can lead to more severe illness than Clade II, which has been spreading in the U.S. for more than two years and prompted the WHO to issue a similar global emergency declaration in 2022.