Doctors have warned that the London Underground could be a hotbed for the spread of coronavirus, hours after the first confirmed case emerged in south London.
A total of nine people in the UK are now being treated for COVID-19, the disease caused by coronavirus, with the latest patient currently being treated at Guy's and St Thomas' Hospital.
There are concerns that the capital's status as a transport hub, and its extremely high population density could exacerbate the spread of the virus, though doctors have said the risk of infection for Londoners and the rest of the UK remains low.
Dr Robin Thompson of Oxford University said: "In general, if an initial case is in a densely populated area, then the risk of sustained person-to-person transmission following is higher."
"This is exacerbated by the fact that London is a transport hub, and the underground could provide a network to spread the virus quickly.
"As a result, given this case was in London, it might be expected that there is an increased risk posed by this case compared to the others we have seen."
London's tube network sees over a billion passengers a year, and stretches throughout south London through Sydenham, Penge West and Becknham, West and East Croydon, Mitcham, Morden, Clapham, Tooting, Wimbledon and Richmond.
While the patient has now been quarantined at St Thomas' Hospital, Dr Thompson says the risk of the virus spreading depends on the woman's interactions prior to being placed in isolation.
"The key factor here is the number of contacts that this infected individual has had prior to being isolated," he said.
"If this is low, then the risk of sustained human-to-human transmission is also low."
As Public Health England investigates the patient's movements, Dr Nathalie MacDermott from the National Institute for Health Research said London commuters should continue to go about their business as usual.
"Provided the individual followed the government's advice (to self-isolate) there should be little concern of transmission to the general public in London," she said.
Everyone is being reminded to follow Public Health England advice to:
- Always carry tissues with you and use them to catch your cough or sneeze. Bin the tissue and wash your hands or use a sanitiser gel.
- Wash your hands often with soap and water, especially after using public transport. Use a sanitiser gel if soap and water are not available.
- Avoid touching your eyes, nose and mouth with unwashed hands.
- Avoid close contact with people who are unwell.
You can find the latest information and advice from Public Health England at www.gov.uk/coronavirus