Health authorities said the risk to the general public remains low.
A case of the contagious new mpox strain at the centre of an outbreak in Africa has been detected in the UK.
The case was identified in London, and the patient has been hospitalised. The patient had recently travelled to African countries experiencing the spread of the virus, according to the UK Health Security Agency (UKHSA).
“The risk to the UK population remains low, and we are working rapidly to trace close contacts and reduce the risk of any potential spread,” said UKHSA chief medical adviser Susan Hopkins.
Mpox spreads through close personal contact, including sex, and symptoms include rash, fever, chills, and swollen lymph nodes.
While mpox has long been endemic in parts of Central and West Africa and caused a global outbreak in 2022, the new strain, called clade 1b, appears to spread more easily and is causing more illness among children.
It first emerged in the Democratic Republic of the Congo (DRC) last autumn and has since been detected in Burundi, Rwanda, Uganda, and Kenya.
The UK patient is the third case of the new mpox strain detected in Europe, with the first in Sweden in August and the second in Germany earlier this month.
At the time, European health authorities said that while they expected more cases to appear, the risk to the public remained low.
The new strain was also identified in India in September and in Thailand in August.
“The number of cases reported outside of Africa remains low, but the ability of Clade 1b virus to spread by human to human transmission means that this issue can not be ignored,” Jonathan Ball, a professor of molecular virology at Liverpool School of Tropical Medicine, said in a statement.
In August, the World Health Organization (WHO) declared the mpox outbreak an international health emergency.
The European Union and several member countries, along with the United States and Danish vaccine-maker Bavarian Nordic, have pledged to donate 620,000 mpox vaccines to the African countries hardest hit by the outbreak. Japan plans to send 3 million jabs.
Including all strains, the Africa Centres for Disease Control and Prevention (Africa CDC) estimates there have been nearly 46,000 mpox cases and more than 1,000 deaths in 18 African countries this year.
“It is unlikely that we will see extensive outbreaks in countries with well developed public health and surveillance systems, but [the new UK case] is a reminder that we need to do more to remove health inequalities around the world,” Ball said.