New Recombinant Mpox Strain Identified in England Following Travel to Asia

UKHSA Confirms Novel Mpox Strain

The U.K. Health Security Agency (UKHSA) has announced the identification of a new recombinant mpox virus in England. The strain was detected in a person who had recently travelled to Asia, marking a significant development in the ongoing monitoring of the virus. Genomic sequencing revealed that this new strain contains elements from both clade 1b and clade 2b mpox, two lineages currently circulating globally.

Dr. Katy Sinka, Head of Sexually Transmitted Infections at UKHSA, commented on the discovery, stating, 'Our genomic testing has enabled us to detect this new mpox strain. It's normal for viruses to evolve, and further analysis will help us understand more about how mpox is changing.'

Understanding the Recombinant Virus

The term 'recombinant' indicates that the new virus has exchanged genetic material from different viral strains. This particular recombination involves clade 1b, which emerged in the Democratic Republic of the Congo (DRC) in 2023 and is considered more transmissible and virulent, and clade 2b, the less severe strain responsible for the 2022 global mpox outbreak.

Experts have voiced concerns regarding this evolution. Dr. Jonas Albarnaz, Institute Fellow at Pirbright Institute, noted that the detection 'is concerning because this shows that the continued global circulation of mpox since 2022 is enabling the virus to evolve in the human population.' Prof. Trudie Lang, Director of the Global Health Network at the University of Oxford, added that this finding is 'precisely what experts in the field feared would happen' and underscores that mpox remains a global health problem.

Mpox: Symptoms, Transmission, and Prevention

Mpox, formerly known as monkeypox, is a viral illness that typically presents with flu-like symptoms followed by a characteristic rash.

• Common symptoms include:
• Skin rash, lesions, or blisters
• Fever and chills
• Headache and muscle aches
• Swollen lymph nodes
• Fatigue

Transmission primarily occurs through close physical contact with an infected individual, including skin-to-skin contact, sexual contact, and contact with contaminated materials like bedding or clothing. It can also spread through respiratory secretions during prolonged face-to-face contact.

While mpox is often mild and resolves within a few weeks, it can lead to severe illness, particularly in vulnerable populations such as young children, pregnant individuals, and those with compromised immune systems. Vaccination is recommended for eligible groups and has proven effective in protecting against severe disease. The NHS offers the mpox vaccine to those considered at higher risk, including men who have sex with men and have multiple partners.

Global Context and Ongoing Surveillance

The mpox virus was first identified in monkeys in 1958, with the first human case recorded in 1970 in the Democratic Republic of the Congo. The World Health Organization (WHO) declared a public health emergency of international concern in 2022 due to a global outbreak of clade 2b, and again in 2024 for the clade 1b outbreak, which was lifted in September 2025.

The UKHSA has shared its findings with international partners, including the WHO, to support global monitoring efforts. The agency continues to assess the significance of this new recombinant strain.