WHO reports new recombinant mpox strain detected in UK, India, urges to monitor
By Anjali Sharma
UNITED NATIONS – World Health Organization said on Sunday that the detection of a newly identified recombinant mpox virus contained genetic material from 2 known strains underscored the need for continued genomic surveillance, as the overall global public health risk assessment remains unchanged.
WHO also confirmed that 2 cases of the recombinant strain combined genomic elements of clades Ib and IIb of the monkeypox virus have been identified to date: 1 in the UK one and 1 in India.
Both patients had recent travel histories, and neither experienced severe illness, UN agency stated.
It added that no secondary cases were detected following contact tracing.
WHO has published a detailed update on the two cases and the national responses.
It noted that recombination is a natural process that can occur when 2 related viruses infect the same person and exchange genetic material, producing a new variant.
According to WHO, detailed genomic analysis showed the two individuals “fell ill several weeks apart with the same recombinant strain,” suggested that additional undetected cases may exist.
The case in the UK was detected in December 2025 in a traveler returning from a country in the Asia Pacific region. Initial laboratory testing identified the virus as clade Ib, but whole genome sequencing later revealed that it contained genetic regions from both clade Ib and clade IIb strains. Repeat sequencing confirmed the findings and demonstrated that the virus “can replicate and presents potential for onward transmission.”
WHO said that in India, a patient who developed symptoms in September 2025 was initially classified as infected with clade II MPXV.
The virus was reclassified as the same recombinant strain identified in the UK after updates to global genomic databases.
UN agency said that the Indian case represents the earliest known detection of this strain.
WHO said “Due to the small number of cases found to date, conclusions about transmissibility or clinical characterization of mpox due to recombinant strains would be premature, and it remains essential to maintain vigilance regarding this development,”.
The clinical presentations in both cases were consistent with known mpox infections.
WHO overall risk assessment remains unchanged: the risk is assessed as moderate for men who have sex with men with new and/or multiple partners and for sex workers or others with multiple casual sexual partners, and low for the general population without specific risk factors.
The agency cautioned that clade differentiation PCR tests alone “may not reliably identify recombinant MPXV strains,” meaning genomic sequencing is essential for detection.
WHO said “All countries should remain alert to the possibility of MPXV genetic recombination.”
It urged continued epidemiological surveillance, sequencing, vaccination of at-risk groups, and infection prevention and control measures.
WHO advised that no travel or trade restrictions are warranted based on current information.
