LONDON — British health officials have confirmed four instances of a new, more transmissible variant of mpox that has its origins in Congo. This development marks the first time this variant has resulted in a cluster of cases outside the African continent. According to scientists, the overall risk to the public remains low.

Authorities reported the first detection of the new variant in the U.K. last week, indicating that the individual was being treated at a hospital in London following recent travel to several African nations that are currently facing mpox outbreaks. This week, the U.K. Health Security Agency announced the identification of three additional cases linked to the initial patient, all of whom reside in the same household and are now receiving treatment in London as well.

“Mpox is highly transmissible within households due to close contact, so it was anticipated that more cases could arise within the same home,” stated Susan Hopkins, the chief medical advisor for the U.K. Health Security Agency.

The new variant of mpox was initially discovered earlier this year in eastern Congo. Experts believe that it leads to less severe symptoms that are also more difficult to recognize, which increases the chance of transmission as individuals may remain unaware of their infection. The algorithm of its spread in Congo and other African countries compelled the World Health Organization to declare a global health emergency in August.

In 2022, the U.K. faced an outbreak of another mpox variant, recording over 3,000 cases that affected more than 100 nations. The new variant has triggered outbreaks in several countries, including Burundi, Kenya, Rwanda, and Uganda. Isolated incidents among travelers have also been noted in Sweden, India, Germany, and Thailand.

Currently, around 43,000 suspected mpox cases have been reported in Africa, with more than 1,000 fatalities, predominantly in Congo.

In response to the ongoing crises, the World Health Organization announced on Wednesday that it has distributed nearly 900,000 vaccine doses to nine African nations grappling with mpox outbreaks.