The first case of a new, more dangerous strain of mpox has been found in Britain, the UK Health Security Agency said.

The patient, who had recently returned from Africa, has been moved to a high-level isolation unit at the Royal Free Hospital in north London, the same facility where imported Ebola cases were treated in 2015.

The strain of the virus, known as clade 1b mpox, is a different variant to those circulating in the UK since 2022 and is believed to cause more severe illness.

Formerly known as monkeypox, the disease is primarily spread through close contact, such as sex, skin-to-skin contact, and talking or breathing near another person.

Mpox causes a characteristic lumpy rash with pus-filled lesions, fever, aches and pains. It has also been linked to dangerous complications for pregnant women, including miscarriage.

The mutant strain of mpox was first detected in the Democratic Republic of the Congo (DRC) last year and has since infected more than 25,000 people and been responsible for the deaths of more than 1,000.

The World Health Organization declared a global health emergency earlier this year due to the rapid spread of clade 1b to neighboring African countries. It has since been detected in Sweden, Germany, India and Thailand, all in patients who had traveled to affected areas.

The UK Health Security Agency (UKHSA) and the NHS said they will study the patient to better understand the new strain of mpox and “learn more about the severity, transmission and control measures,” the agency said in a statement. .

Health and Social Care Secretary Wes Streeting said: “The overall risk to the UK population currently remains low and the Government is working alongside the 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.”

The UKHSA says it will not reveal any further information about the patient, but confirmed he had traveled to countries in Africa “that are seeing community cases of Clade 1b mpox”.

Cases in the Democratic Republic of the Congo (the epicenter of the outbreak) continue to rise, despite the recent rollout of vaccines that are reportedly taking longer than expected to reach the worst-affected areas.

The campaign launched earlier this month in the country’s hardest-hit regions, with shots donated by international partners including the United States, the European Union and Japan.

The limited supply means there are only 265,000 doses currently available in the country of around 100 million people.

Protect yourself and your family by learning more about Global health security

Broaden your horizons with award-winning British journalism. Try The Telegraph free for 3 months with unlimited access to our award-winning website, exclusive app, money-saving offers and more.