Despite a decline in global cases following the World Health Organization’s lifting of the public health emergency in September 2024, mpox continues to evolve and circulate internationally. Health officials in the United Kingdom have identified a new strain of the virus in a traveler recently arriving from Asia, prompting increased surveillance efforts [[1]]. The newly identified variant contains genetic material from two previously known sub-types, raising concerns among researchers about its potential impact on transmission and severity [[2]]. The UK Health Security Agency (UKHSA) is currently investigating the case and urging vigilance as the virus demonstrates its ability to mutate [[3]].
London – Health officials in the United Kingdom have identified a new strain of mpox in a recent traveler from Asia, prompting increased global vigilance regarding the evolving virus formerly known as monkeypox. The discovery highlights the ongoing need for monitoring as the virus continues to circulate and change.
“Our genomic testing has allowed us to detect this new mpox strain,” said Katy Sinka of the UK Health Security Agency (UKHSA) in a statement on Monday, December 8, 2025.
The UKHSA is a government agency responsible for protecting the nation’s health by preventing and controlling infectious diseases.
According to the UKHSA, the newly identified strain contains elements from two different mpox sub-types: clade 1, which is associated with more severe illness, and clade 2, which has been the dominant strain in recent global outbreaks. “Genomic sequencing shows that the mpox genome contains elements of both clade Ib and clade IIb mpox,” the agency stated.
Potential for Spread
Mpox is a viral infection similar to smallpox that can cause fever, body aches, and skin lesions, and can be potentially fatal. Transmission occurs through close physical contact, from animal to human or between people.
“Viruses do evolve, and further analysis will help us better understand how mpox is changing,” Sinka explained.
Researchers at the University of Oxford have expressed concern about the emergence of this recombinant strain. “It is worrying to see mpox cases in the UK, and even more concerning that this is a new, recombinant mpox virus,” said Trudie Lang, a researcher at the university.
Lang added that this case confirms mpox continues to circulate and evolve globally, consistent with previously predicted patterns.
The World Health Organization (WHO) declared mpox a public health emergency in August 2024 following a large outbreak in the Democratic Republic of Congo and its spread to several countries. The emergency status was lifted in September 2024 as case numbers and deaths began to decline.
However, the virus’s evolution continues. Lang noted that previous mpox strains were more often transmitted from animals to humans, while the 2022 European outbreak spread through close sexual contact, particularly among gay and bisexual men.
Boghuma Titanji, an assistant professor of medicine at Emory University, said the finding aligns with what scientists have anticipated. “The identification of a recombinant mpox strain containing elements of clade I and clade II is exactly what experts in the field have feared,” she stated.
As of the end of October 2025, more than 48,000 confirmed cases of mpox had been reported to the WHO from 94 countries, resulting in 201 deaths. The UK continues to identify “low levels” of cases since the global outbreak in 2022.
The UK government has a vaccination program for mpox targeting at-risk groups, including individuals with multiple sexual partners or those who engage in group sex.
This latest case has prompted the UKHSA to increase monitoring and is a reminder to the public to remain vigilant for potential spread of the new strain.
