UK identifies new recombinant mpox strain in traveler returning from Asia

Health officials in the United Kingdom have identified a new recombinant strain of mpox in an individual who recently returned from abroad, according to the UK Health Security Agency (UKHSA).

The case was identified in England in an individual who had recently traveled to Asia, according to a statement from UKHSA on Monday. Genomic sequencing showed that the mpox genome contained elements of clade Ib and clade IIb.

“This is not unexpected as both clades are circulating, but highlights the continued potential for mpox virus to evolve and the importance of continued genomic surveillance,” the statement said. The agency said it is still assessing the significance of the strain.

Dr. Katy Sinka, Head of Sexually Transmitted Infections at UKHSA, said genomic testing enabled the detection of the new variant. “It’s normal for viruses to evolve, and further analysis will help us understand more about how mpox is changing,” she said. She urged eligible individuals to get vaccinated, noting that infection “can be severe” despite being mild for many people.

Mpox viruses are grouped into genetic families known as clades, with clade I historically linked to more severe disease in parts of Central Africa and clade II associated with the global outbreaks that began in 2022.

According to the Pan American Health Organization (PAHO), more than 168,000 confirmed mpox cases have been reported worldwide between 2022 and October 2025, spanning 142 countries and territories. PAHO said the Americas have reported the largest share of infections at 42%, followed by Africa at 36% and Europe at 19%.

UKHSA said findings from the case have been shared with international partners, including the World Health Organization, to support global monitoring efforts. The individual’s condition was not released.