Two more cases of a new, more dangerous mpox strain, known as Clade 1b, have been confirmed in London, according to the UK Health Security Agency (UKHSA). The patients, who are being treated at Guy’s and St Thomas’ NHS Foundation Trust, are members of the same household as the UK’s first confirmed case of the strain, which was reported last Friday.
Professor Susan Hopkins, UKHSA’s Chief Medical Adviser, noted that close-contact settings, such as households, heighten the risk of transmission. “Mpox is very infectious in households with close contact, so it is not unexpected to see further cases within the same household,” she said while adding that the overall risk to the UK population remains low. Health authorities are currently reaching out to other contacts for testing and vaccination as needed.
The initial case, diagnosed last week, involved a traveller who returned from an affected area in Africa on October 21. The newly detected Clade 1b variant differs from previous Mpox strains found in the UK and is believed to cause more severe illness and spread more easily between individuals.
Originating in the Democratic Republic of Congo last year, Clade 1b has since infected over 25,000 people and caused at least 1,000 deaths, prompting the World Health Organisation (WHO) to declare a global health emergency earlier this year. The strain has spread beyond Africa, with cases reported in Sweden, Germany, India, and Thailand, primarily in patients who had travelled to impacted regions.
Mpox, previously known as monkeypox, is primarily transmitted through close contact, including skin-to-skin interactions and respiratory droplets. The disease often leads to a distinctive lumpy rash, fever, and aches, and can pose serious risks for pregnant women, including miscarriage.
Health authorities urge anyone who may have been exposed or is experiencing symptoms to seek medical advice.
