UK detects first case of new mpox variant

One person in London has tested positive for the more infectious form of mpox after traveling to Africa, according to British health officials. It’s the first known case in the UK of the new variant.

The UK Health Security Agency (UKHSA) said the person, whose age and gender has not been disclosed, tested positive in London and has since been transferred to Royal Free Hospital’s High Consequence Infectious Diseases unit.

“They had recently travelled to countries in Africa that are seeing community cases of Clade Ib mpox,” UKHSA said in a statement. “The UKHSA and NHS will not be disclosing any further details about the individual.”

Close contacts of the case are being followed up by UKHSA and partner organisations, and all of them will be offered testing if they have any symptoms. They may also be offered vaccination.

“UKHSA, the NHS and partner organisations have well tested capabilities to detect, contain and treat novel infectious diseases, and while this is the first confirmed case of mpox Clade Ib in the UK, there has been extensive planning underway to ensure healthcare professionals are equipped and prepared to respond to any confirmed cases,” the agency said.

In August, the World Health Organization (WHO) declared mpox a Public Health Emergency of International Concern, and Africa CDC issued its first-ever public health emergency to mobilize resources across the continent.

More than 34,000 confirmed and suspected cases have been reported across Africa so far this year, an increase of more than 200% compared to 2023. More than 1,000 people have died. In one of the hardest-hit countries, the DR Congo, only 20% of suspected cases were able to get tested.

Of particular concern is clade 1b, which is causing more severe disease compared to the variant which spread around the world in 2022. It’s also believed to be more infectious. While clade 2b mainly spreads through sexual contact, the new strain may also spread among close contacts.

Travel-associated cases of clade 1b have also been reported in Germany, India, Kenya, Sweden and Thailand.