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expert reaction to confirmed case of COVID-19 (coronavirus) in London

There has been a confirmed case of COVID-19 in London. The individual had recently travelled from China. 


Dr Michael Head, Senior Research Fellow in Global Health, University of Southampton, said:

“The extensive London public transport system provides potential opportunities for transmission, with many people mixing in relatively small spaces. However, the evidence related to ground transportation as a key factor in transmission of respiratory infectious disease is actually fairly limited. Whilst studies have linked some transmission of flu to use of public ground transport, it is not normally the main factor in the spread of an outbreak due to relatively short time periods of being in close proximity to an infected case. For example, studies suggest possible transmission on long-distance trains, but less so on shorter journeys such as on the London Underground. In terms of previously studied respiratory diseases such as flu, we have evidence that international travel is usually a more important factor for spread, in part due to time spent near an infectious person.


 Dr Robin Thompson, Junior Research Fellow in Mathematical Epidemiology, University of Oxford 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. However, the key factor here is the number of contacts that this infected individual has had prior to being isolated.  If this is low, then the risk of sustained human-to-human transmission is also low. Contact tracing will now be being carried out. Contact tracing followed by isolation of individuals who may have been infected is very important to prevent sustained transmission occurring within the UK.”


Prof Jon Cohen, Emeritus Professor of Infectious Diseases, Brighton & Sussex Medical School, said:

“It is really not surprising that a case has been reported from London. London is a major international travel hub which receives large numbers of travellers from many parts of the world, including those areas in SE Asia which have borne the brunt of the cases. The public health authorities will be following up closely and will be checking on possible contacts. We will not really be able to estimate the potential risk of onward spread until further information on this patient is known, including details of how long they were in the UK until they were diagnosed and what their movements were. Anyone who believes they may have been in contact with this patient should follow the advice which has been widely published, self-isolate and call the NHS 111 number for advice.”

Dr Michael Tildesley, Associate Professor in Mathematical Epidemiology, University of Warwick, said:

“It has been confirmed this is a case where an individual has travelled from China and has been detected whilst in London. So we don’t have enough evidence at this stage to say that it is spreading in London – we have had an introduction of the virus to London from an individual that has travelled from China but as yet, no reported human-to-human transmission as a result of this new case. There always remains the risk of introduction of cases into the UK from international travellers and it is difficult to predict where future introductions may occur. So it’s not surprising that there is a case in London since it is the main UK hub for international travellers. What needs to be done at this stage is to carry out contact tracing, in a similar way that has been done for other cases, in order to detect any contacts as rapidly as possible and if they show symptoms of the disease, follow the necessary protocols to minimise the risk of them causing further infections. It is important of course that people remain vigilant and minimise their own risk of being infected but at this stage it is too early to say the extent of the risk of onward transmission as a result of this new case.”

Dr Nathalie MacDermott, NIHR Academic Clinical Lecturer, King’s College London (KCL), said:

“A ninth case of SARS-COV-2 infection/COVID-19 has been identified in the UK. This is not surprising, over the last couple of weeks it has been clearly stated that further cases may be expected in the UK. This case was identified in London and according to Prof Whitty’s statement contracted their infection in China. It is unclear what part of China this individual has travelled from and whether they followed the UK government’s advice to self-isolate for 14 days in the absence of symptoms (if from Wuhan or Hubei province) or to self-isolate as soon as symptoms were noticed (rest of China), but hopefully this information will be made clear in the coming days. Provided the individual followed the government’s advice there should be little concern of transmission to the general public in London, although close contacts of the case may be at risk of being infected. Public Health England will have commenced contact tracing and will contact anyone who may be at risk of infection and request they self-isolate for 14 days to limit any onward transmission of infection.”

Dr Michael Head, Senior Research Fellow in Global Health, University of Southampton, said:

“If confirmed, it is not surprising that London has seen its first case of the coronavirus. It’s a city of over 10 million people with several major international airports. Both London and the rest of the UK can expect to see more cases, though hopefully these will continue to be isolated cases and seen in small numbers. It should also be noted that of the 1750 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.”

All our previous output on this subject can be seen at this weblink:

Our factsheet on the outbreak is available here:
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