California confirms first known U.S. case of deadlier mpox strain

The California Department of Public Health Saturday reported the first known case of clade I mpox in the U.S. to the Centers for Disease Control and Prevention. Clade I is a more severe strain of the infection than clade II, the strain of mpox that has been circulating in the U.S. since 2022. The infected individual is isolating at home and risk to the public remains low, both agencies said.

The CDC said that the individual recently traveled from East Africa, where clade I has been prevalent. The World Health Organization Aug. 14 declared a global health emergency due to an outbreak of clade I in the eastern and central African regions.