The number of confirmed cases of monkeypox in the UK has passed 300.

At least one patient has been treated at the Royal Free Hospital in Hampstead, but the authorities are not saying how many cases it is now handling.

The Royal Free London NHS Foundation Trust is referring all questions to the UK Health Security Agency (UKHSA), which says it does not hold a breakdown of cases by trust.

The UKHSA said on Monday there are currently 287 confirmed cases in England, 10 in Scotland, two in Northern Ireland and three in Wales.

The agency says the overall risk to the UK population remains low.

Members of the England’s High Consequence Infectious Diseases (HCID) network – including the Royal Free – contributed to new research on monkeypox in the UK.

Published in The Lancet Infectious Diseases, the report includes analysis of seven monkeypox cases between 2018 and 2021.

It is the first study of its kind and demonstrated prolonged viral positivity within a variety of areas of the body, changing the understanding of the biology of the disease.

Jake Dunning, clinical lead for HCID at the Royal Free and co-author of the study, said:

“Since we set up the national HCID programme in 2016, and the Royal Free London team diagnosed the first travel-associated case outside Africa in 2018, we have been working on preparing to care for and study more cases.

Therefore, detailed clinical and virological information like this is important, not only for the current, unprecedented outbreaks we are seeing, but for improving our understanding of monkeypox generally.”

Symptoms of the virus include fever, a characteristic rash, and swelling of the lymph nodes. Complications are uncommon, but can include inflammation of the lungs, brain and eyes, along with secondary bacterial infections.

In its latest update, the UKHSA said anyone can get monkeypox through close contact, including sexual contact, with an individual with symptoms. It said: "People who are gay or bisexual and men who have sex with men remain disproportionately affected."

Anyone with unusual rashes or lesions on any part of their body, especially their genitalia, should contact NHS 111 or call a sexual health service if they have concerns, it said.