The first confirmed case of Clade Ib mpox has been detected in the UK, public health officials have announced.
The UK Health Security Agency (UKHSA) said the case had been identified in London in an individual who had recently travelled to countries in Africa that are seeing outbreaks.
Clade Ib mpox is new variant of the virus which has been causing concern because it appears to spread more easily.
In August, the UKHSA updated its advice to raise awareness of the variant among doctors after the World Health Organisation declared it to be a public health emergency.
The variant has been widely circulating in the Democratic Republic of Congo (DRC) in recent months and there have been cases reported in Burundi, Rwanda, Uganda, Kenya, Sweden, India and Germany.
But UKHSA said that the risk to the UK population remains low, with extensive planning in place to ensure healthcare professionals are equipped and prepared to respond to any confirmed cases.
Close contacts of the case are being followed up by UKHSA and partner organisations and the individual is being treated at the Royal Free Hospital High Consequence Infectious Diseases unit.
In September, the Government said it had purchased more than 150,000 doses of mpox vaccine which it would be rolling out to eligible groups in stages.
The existing evidence suggests mpox Clade Ib causes more severe disease than Clade II, which has been circulating at low levels in the UK since 2022, primarily among gay, bisexual and other men-who-have-sex-with-men.
Researchers would continue to monitor and learn more about the severity, transmission and control measures, UKHSA said.
Professor Susan Hopkins, UKHSA chief medical adviser, said: ‘This is the first time we have detected this Clade of mpox in the UK, though other cases have been confirmed abroad.
‘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.
‘In accordance with established protocols, investigations are underway to learn how the individual acquired the infection and to assess whether there are any further associated cases.
Health and social care secretary Wes Streeting said he was extremely grateful to the healthcare professionals supporting and caring for the patient affected.
He said: ‘The overall risk to the UK population currently remains low and the government is working alongside UKHSA and the NHS to protect the public and prevent transmission.
‘This includes securing vaccines and equipping healthcare professionals with the guidance and tools they need to respond to cases safely.’
Steve Russell, NHS national director for vaccination and screening, said: ‘Since mpox first became present in England, local services have pulled out all the stops to vaccinate those eligible, with tens of thousands in priority groups having already come forward to get protected, and while the risk of catching mpox in the UK remains low, if required the NHS has plans in place to expand the roll out of vaccines quickly in line with supply.’
Dr Brian Ferguson, associate professor of immunology at the University of Cambridge said the case was not surprising.
‘The Clade Ib mpox is more virulent than Clade II virus that caused the outbreak in 2022 and is causing more cases of disease in younger people than the Clade II virus in Africa.
‘As such continued surveillance and early diagnosis and treatment is very important to minimise the chances of onward transmission of imported cases.’
Lock up your pet monkeys