/connect-gujarat-english/media/media_files/2025/04/08/yO0vQpZeHnRXhehO2sB3.jpeg)
Efforts were ongoing to determine where the individual, who lives in northeastern England, may have caught the infection, the UK Health Security Agency (UKHSA) said in a statement.
All previously confirmed cases had either travelled to an affected area or had links to someone who had done so, it said.
UKHSA mpox incident director Gillian Armstrong said the "risk to the UK population from mpox remains low" despite the unexplained case.
Mpox is a viral disease related to smallpox, and has two main subtypes -- clade 1, which mainly affects children, and clade 2.
Symptoms include fever, a skin rash or pus-filled blisters, swollen lymph nodes and body aches.
The WHO first declared an international public health emergency in 2022 over the spread of clade 2. That outbreak mostly affected gay and bisexual men in Europe and the United States.
Vaccination and awareness drives in many countries helped stem the number of worldwide cases and the WHO lifted the emergency in May 2023 after reporting 140 deaths out of around 87,400 cases.