Smallpox is a rare viral infection that does not spread easily among humans, the agency said, describing the overall risk to the general public as “very low”.
“The infection can spread when someone is in close contact with an infected person; however, there is a very low risk of transmission to the general population,” the statement said.
The patient is believed to be infected in Nigeria, the UKHSA reported, before she recently traveled to the UK. He or she is being treated in London by the Infectious Diseases and Isolation Unit at Guy’s and St Thomas ’NHS Foundation Trust.
According to the UKHSA, initial symptoms include fever, headache, muscle aches, back pain, swollen lymph nodes, chills and exhaustion.
UKHSA said it would contact people “who may have been in close contact with the person to provide them with information and health advice” as a precaution.
Rodents, including animals kept as pets, and monkeys can carry monkeypox and transmit it to humans. The CDC investigated one case of passengers in Dallas last year.