The United Kingdom has identified another case of a contagious new strain of mpox, making it the latest European country to report an infection.
The new strain has infected thousands of people in Central Africa since it emerged in the Democratic Republic of the Congo (DRC) in 2023.
There are two subtypes of the mpox virus. Clade II, which is endemic in West Africa, caused the global outbreak that had health authorities on high alert in Europe and North America in 2022. It continues to spread there at low levels.
Meanwhile clade I, which is endemic in Central Africa, is believed to cause more severe illness and a greater risk of death.
A subset of the more dangerous strain, known as clade Ib, was identified in the DRC in September 2023 and has since spread widely across the region, particularly in Burundi and Uganda.
How does mpox spread?
Much is still unknown about the severity of mpox caused by clade Ib, but it appears to spread more easily and is causing more illness among children.
Mpox spreads through close skin-to-skin contact, and can cause a rash, headache, fever, chills, lymph node swelling, and respiratory symptoms.
The World Health Organization (WHO) declared Africa’s mpox outbreak a global public health emergency in August 2024. At the time, European health authorities warned that cases would likely emerge in Europe as well, though the risk to the public remains low.
Outside of Africa, the new strain has since been detected in five European countries as well as the United States, Canada, Brazil, China, India, Thailand, Oman, Pakistan, Qatar, and the United Arab Emirates (UAE).
Here’s where the new mpox strain has been found so far in Europe.
United Kingdom
Most of the UK's 11 mpox clade Ib cases have been travel-related. But the most recent infection, reported in April, was a person who had not travelled recently and had no link to previously confirmed cases, the UK Health Security Agency said.
The agency said no more cases were identified among the person’s close contacts, and that the risk to the public remains low.
The UK’s first cases were in October 2024, when a person got sick after returning from African countries where the strain is circulating and then spread mpox to three members of their household.
In September, the UK government bought more than 150,000 doses of mpox vaccine to prepare for potential clade Ib risks, and recently opened vaccination sites across England.
Germany
Germany has reported eight mpox clade Ib cases, most recently in February. Its first case was in October, with five more infections in December, the European Centre for Disease Prevention and Control (ECDC) said.
The December cases involved someone who had travelled to an area affected by the outbreak and then infected family members, including children who had not been overseas recently, the ECDC said. There was no additional spread outside of the household.
Belgium
Belgium has identified five cases. The first were in December, among an infected person who had recently travelled abroad and a child. The ECDC said at the time it had not identified any high-risk contacts.
The country reported additional cases this year: one in January and two in February.
France
In January, French health authorities said someone in the region of Brittany got mpox after close contact with two people who had travelled from Central Africa. Another case was reported in February, the ECDC said.
National authorities said that additional cases linked to countries with mpox outbreaks may emerge on occasion.
Sweden
In August 2024, Sweden became the first country outside of Africa to report a case of the new mpox strain.
A patient sought medical care in Stockholm after being infected in a part of Africa where clade Ib mpox is spreading, Swedish health authorities said. It remains the country’s only case.
Ireland
In February, Irish health authorities detected one case of clade Ia mpox, which is different from the new strain but still causing concern in Africa.
The infected person had recently returned from the DRC and was hospitalised in Dublin. At the time, authorities said the risk to the public remained low.
