Two more cases of a new strain of mpox have been detected in the UK, officials say.
Last week, the UK Health Security Agency (UKHSA) said a single case of the mpox virus variant Clade 1b had been confirmed in London.
The agency has now announced a further two cases – in household contacts of the first case.
The two patients are currently under specialist care at Guy’s and St Thomas’ NHS Foundation Trust in London, it added.
“The risk to the UK population remains low,” the UKHSA said.
“There has been extensive planning under way to ensure healthcare professionals are equipped and prepared to respond to any further confirmed cases.”
The UKHSA’s chief medical adviser, Professor Susan Hopkins, said: “Mpox is very infectious in households with close contact and so it is not unexpected to see further cases within the same household.
“The overall risk to the UK population remains low. We are working with partners to make sure all contacts of the cases are identified and contacted to reduce the risk of further spread.”
The first case detected in London last week was a person who had been on holiday in Africa.
They developed flu-like symptoms more than 24 hours after returning to the UK and later developed a rash which worsened in the following days.
The agency said contacts of all three cases are being followed up on and would be offered testing and vaccination as needed.
What are the symptoms of mpox and how is it passed on?
Common symptoms of the disease include a skin rash or pus-filled lesions, which can last between two to four weeks. It can also cause fever, headaches, muscle aches, back pain, low energy and swollen lymph nodes.
Mpox, and the Clade 1b strain, is usually passed on by close physical contact, contact with infected animals, or sexual transmission.
The UK has a stock of mpox vaccines and last month announced more were being procured to support a routine immunisation programme.