The patient has a recent travel history from Nigeria, which is where they are believed to have contracted the infection, before travelling to the UK.
Monkeypox is a rare viral infection that does not spread easily between people. It is usually a mild self-limiting illness and most people recover within a few weeks. However, severe illness can occur in some individuals.
The infection can be 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 patient is receiving care at the expert infectious disease unit at the Guy's and St Thomas' NHS Foundation Trust, London.
As a precautionary measure, UKHSA experts are working closely with NHS colleagues and will be contacting people who might have been in close contact with the individual to provide information and health advice.
This includes contacting a number of passengers who travelled in close proximity to the patient on the same flight to the UK. People without symptoms are not considered infectious but, as a precaution, those who have been in close proximity are being contacted to ensure that if they do become unwell they can be treated quickly. If passengers are not contacted then there is no action they should take.
Dr Colin Brown, Director of Clinical and Emerging Infections, UKHSA, said:
It is important to emphasise that monkeypox does not spread easily between people and the overall risk to the general public is very low.
We are working with NHS England and NHS Improvement (NHSEI) to contact the individuals who have had close contact with the case prior to confirmation of their infection, to assess them as necessary and provide advice.
UKHSA and the NHS have well established and robust infection control procedures for dealing with cases of imported infectious disease and these will be strictly followed.
