Doctors have warned the London Underground network could be a hotbed for the spread of the strain of coronavirus known as Covid-19.
The warning comes after a London woman became the ninth person in the UK to test positive for the deadly virus.
Wednesday proved to be the disease's deadliest day in China, with 254 deaths reported, bringing the total to more than 1,360.
In the rest of the world more than 400 cases have been confirmed across 24 countries and only two deaths have occurred outside of mainland China.
There are concerns the London's status as a transport hub could exacerbate the spread of coronavirus, however doctors have said the risk of infection for residents in the capital remains low.
"In general, if an initial case is in a densely populated area, then the risk of sustained person-to-person transmission following is higher," Dr Robin Thompson of Oxford University said.
"This is exacerbated by the fact that London is a transport hub, and the underground could provide a network to spread the virus quickly.
Of the nine people so far diagnosed with coronavirus in the UK, two are GPs who are known to have worked at a nursing home, Worthing Hospital A&E and two GP practices between them.
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He added: "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."
Dr Michael Head from the University of Southampton added: "It should also be noted that of the 1,750 tests carried out so far in the UK, over 99% of those tested have been negative for the coronavirus.
"Thus, risks to Londoners and UK residents remain low, though people should continue to keep an eye on guidance for the general public."
Eighty-three Britons who were rescued from the Chinese city of Wuhan - the epicenter of the outbreak - are to be freed on Thursday after two weeks in quarantine.
The group will leave Arrowe Park Hospital in Merseyside on Thursday, 14 days after they arrived on an evacuation flight.
While the London patient has now been quarantined, 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.