Los Angeles County health officials are investigating the potential local spread of a dangerous new strain of monkeypox, now referred to as Mpox. The strain, known as Clade I, is more severe than previously circulating types and was previously confined to regions in Africa. Three individuals in L.A. County have tested positive without any international travel history, raising serious concern that the virus is spreading locally for the first time.
Clade I mpox is known to cause more severe illness and has a higher transmission rate than the Clade II strain that circulated during the 2022 U.S. outbreak. According to the L.A. County Department of Public Health, all three patients have been hospitalized and are recovering. County Health Officer Dr. Muntu Davis said the confirmation of a third local case with no travel history raises the possibility of community transmission.
Health officials stress that the general public’s risk remains low. However, they are urging increased awareness and rapid testing, particularly among individuals showing symptoms such as rashes, fever, or swollen lymph nodes. The JYNNEOS vaccine, previously used during the 2022 outbreak, remains available and is being encouraged for at-risk individuals.
The Centers for Disease Control and Prevention confirmed that this marks the first time the Clade I strain has been detected in the United States without a link to international travel. Unlike the earlier outbreak tied largely to intimate contact, Clade I is believed to be transmissible through broader close contact, including within households.
