A new case of the highly transmissible Clade Ib variant of mpox – formerly known as monkeypox – has been confirmed in England, marking a total of five detections during the current outbreak. The recent case was identified in Leeds and the patient is currently receiving specialist treatment at Sheffield Teaching Hospitals NHS Foundation Trust.
It’s thought they picked up the infection while in Uganda. Earlier this year four cases of the Clade Ib strain had been recorded within one household in England, with reports now confirming that those affected have “fully recovered”.
Commenting on the situation, UK Health Security Agency (UKHSA)’s chief medical adviser, Professor Susan Hopkins, stated: “It is thanks to clinicians rapidly recognising the symptoms and our diagnostics tests that we have been able to detect this new case. The risk to the UK population remains low following this fifth case, 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.”
The Clade Ib variant of mpox has garnered international attention this year due to an outbreak in Africa. This strain is distinct from Clade II, which has been present in the UK at minor levels since 2022.
Mpox symptoms can range from a skin rash or pus-filled lesions, lasting two to four weeks, to fever, headaches, muscle aches, back pain, low energy and swollen lymph nodes. However, it can be severe and even fatal in vulnerable individuals such as those with weakened immune systems, young children and pregnant women.
The latest outbreak of this strain is believed to have originated in the Democratic Republic of Congo (DRC) in Africa, where 5,399 cases and 25 deaths were reported in the first nine months of 2024. In October, it was disclosed that the number of suspected mpox cases in Africa this year was 42,438, with 8,113 confirmed, according to the Africa Centres for Disease Control and Prevention.
Furthermore, at least 1,000 mpox deaths have been reported in Africa, prompting the World Health Organisation (WHO) to declare a global health emergency for the second time in two years. Other cases of Clade Ib have also been reported in Germany, Sweden, Thailand and India.
The infection can be transmitted through close person-to-person contact with an infected individual or animals, or through contact with contaminated materials. The UKHSA advises anyone exhibiting symptoms to continue avoiding contact with others while symptoms persist.
Symptoms
If you contract mpox, the NHS states that it usually takes between five and 21 days for the initial symptoms to appear. The first symptoms of mpox include:
- Exhaustion
- A headache
- Backache
- A high temperature (fever)
- Shivering (chills)
- Muscle aches
- Swollen glands
- Joint pain
A rash usually appears one to five days after the first symptoms. It can be on any part of the body, including the palms of the hands, soles of the feet, mouth, genitals and anus. You may also have anal pain or bleeding from your bottom.
The rash is sometimes confused with chickenpox. It starts as raised spots, which turn into sores (ulcers) or small blisters filled with fluid. The blisters eventually form scabs which later fall off.