NYC Confirms First Mpox Clade I Case in Traveler

New York City health officials confirmed the city's first case of mpox clade I, a more severe strain of the virus, in a resident who recently traveled internationally. The detection, announced in a health advisory on Friday, marks the 12th such case in the United States since November 2024, with no evidence of local transmission in the city.

The patient tested positive for clade I, one of two main genetic variants of the mpox virus, which health authorities describe as capable of causing more serious illness than clade II, the strain behind a 2022 global outbreak that led to nearly 4,000 cases in New York City alone. Most prior U.S. infections have involved clade II, which has a survival rate exceeding 99.9 percent. In contrast, clade I has been linked to higher rates of severe symptoms and fatalities, particularly in outbreaks in the Democratic Republic of Congo and other parts of Africa since 2024. Officials emphasized that the New York case appears linked to international travel and has not spread within the community.

Mpox spreads primarily through close, intimate contact, such as skin-to-skin touching during sex, hugging, or kissing, as well as through respiratory droplets...