Official announcements from the U.S. Department of State or CDC

First U.S. Case of Clade 1 Mpox Confirmed in San Mateo County

Nov 16, 2024, 07:40 PM

U.S. health officials have confirmed the first known case of a new, more severe strain of mpox, clade 1, in San Mateo County, California. The traveler recently arrived from Eastern Africa and is currently under care. Clade 1 mpox, first seen in eastern Congo, has been causing an outbreak in central Africa and is considered more severe than clade 2, which was responsible for the global outbreak that started in 2022. Mpox is caused by the monkeypox virus (MPXV). Officials note that there is no evidence of local transmission at this time, and further testing is ongoing with no subclade reported yet.