Two more cases of a strain of mpox that is thought to spread more easily have been detected in the UK, health officials have confirmed. This brings the total number of confirmed cases of the Clade Ib mpox strain in the country to three. The UK Health Security Agency (UKHSA) said the risk to the UK population “remains low” and that the two patients are under specialist care at Guy’s and St Thomas’ NHS foundation trust in London.

The first case was detected in London last week in a person who had been on holiday in Africa and travelled back to the UK on an overnight flight on 21 October. They developed flu-like symptoms more than 24 hours later and, on 24 October, started to develop a rash that worsened in the following days.

Contacts of all three cases are being followed up by the UKHSA and other partner organisations and will be offered testing, vaccination and advice as needed. Prof 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 Spread of Mpox

Mpox can spread between people through direct contact with rashes, skin lesions or scabs caused by the virus. This includes during sexual contact, kissing, cuddling or other skin-to-skin contact. It can also spread through contact with body fluids such as saliva or snot; contact with bedding or towels or clothing; and a possibility of spread through close and prolonged face-to-face contact such as 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.

The Clade 1b Strain of Mpox

Clade Ib mpox has been widely circulating in the Democratic Republic of the Congo in recent months. Cases have also been reported in Burundi, Rwanda, Uganda, Kenya, Sweden, India and Germany. A report from the World Health Organization (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, with Clades Ia, Ib and II circulating in the region. The WHO has declared a public health emergency of international concern because of the rapid spread of the mpox strain.

The health secretary, Wes Streeting, said last week that the government was working with 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. We are also working with our international partners to support affected countries to prevent further outbreaks,” he added.

What This Means for the UK

The UKHSA is closely monitoring the situation and working to ensure that healthcare professionals are prepared to respond to any further cases. The agency is also working with partners to make sure that all contacts of the cases are identified and contacted to reduce the risk of further spread. The UK government has a stock of mpox vaccines and last month announced more were being procured to support a routine immunisation programme.

The overall risk to the UK population remains low. However, it is important to be aware of the symptoms of mpox and to take steps to protect yourself and your family. If you have been in close contact with someone who has mpox, or if you have any of the symptoms of mpox, it is important to seek medical attention immediately.

Looking Ahead

The emergence of the Clade 1b strain of mpox highlights the importance of ongoing surveillance and public health measures to prevent the spread of this disease. It is also a reminder that the world is still facing a number of infectious disease threats, and that we must be prepared to respond to them effectively. The UK government is working with international partners to develop new vaccines and treatments to fight mpox and other infectious diseases. With increased vigilance and collaboration, it is possible to protect our communities from these threats and ensure the health and well-being of all.