More cases of deadly mpox strain found in UK one week after first detected in London

More cases of a potentially deadly new strain of have been detected in the UK, officials have announced.

The UK Health Security Agency (UKHSA) said on Monday (November 4) that two further cases were detected in household contacts of the first case. It brings the total number of cases of the Clade Ib mpox strain in Britain to three.

The two patients are under specialist care at Guy's and St Thomas' NHS Foundation Trust in . The UKHSA said the risk to the UK population "remains low".

Professor Susan Hopkins, Chief Medical Adviser at UKHSA, 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 UK case of the mpox strain was detected in London and made public on October 30.

The infected person had been on holiday in and travelled back to the UK on an overnight flight on October 21.

They developed flu-like symptoms more than 24 hours later and on October 24 they started to develop a rash which worsened over the following days.

The person attended an emergency department in London on October 27, where they were swabbed, tested and sent home to isolate while waiting for the results.

They were then transferred to the Royal Free Hospital high consequence infectious diseases unit for treatment.

The UKHSA said at the time that fewer than 10 people who were thought to have come into contact with the patient had initially being traced.

Mpox spread may occur through direct contact with rash, skin lesions or scabs caused by the virus, including during sexual contact, kissing, cuddling or other skin-to-skin contact.

There is also a risk from contact with bodily fluids such as saliva or mucus; contact with bedding, towels or clothing and a possibility of spread through close and prolonged face-to-face contact such as when talking, breathing, coughing, or sneezing.

Symptoms include skin rash with blisters, spots or ulcers that can appear anywhere on the body, fever, headache, backache and muscle aches.

A rash usually appears one to five days after a fever, headache and other symptoms.

Clade Ib mpox has been widely circulating in the Democratic Republic of Congo (DRC) over recent months. Cases have also been reported in Burundi, Rwanda, Uganda, Kenya, Sweden, India and Germany.

A report from the World Health Organisation (WHO) and the Africa Centres for Disease Control and Prevention said there had been more than 40,000 mpox cases linked to almost 1,000 deaths in Africa as of the end of September 2024.

The WHO has declared a public health emergency of international concern because of the rapid spread of the mpox strain.

Some health officials said on Sunday (November 3) that mpox cases in the DRC appeared to be "stabilizing" in a possible sign the main epidemic might be on the decline.

In recent weeks, the DRC has reported about 200 to 300 lab-confirmed mpox cases per week, according to the WHO. That is down from nearly 400 cases a week in July.