January 18, 2020

expert reaction to the Wuhan coronavirus outbreak

continued reaction to the coronavirus outbreak in Wuhan, China.

This reaction was accompanied by an SMC Briefing.

Thursday 23 January

Dr Helena Maier, Head of Nidovirus-Cell Interactions group, The Pirbright Institute, said:

What is a coronavirus and where do they come from?

Coronaviruses are a family of viruses that infect a wide range of different species including humans, cattle, pigs, chickens, dogs, cats and wild animals. Until this new coronavirus was identified, there were six different coronaviruses known to infect humans. Four of these cause a mild common cold-type illness, but since 2002 there has been the emergence of two new coronaviruses that can infect humans and result in more severe disease (Severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS) coronaviruses). Coronaviruses are known to be able to occasionally jump from one species to another and that is what happened in the case of SARS, MERS and the new coronavirus. The animal origin of the new coronavirus is not yet known.

Are all coronaviruses spread in the same way?

Coronaviruses tend to cause either a respiratory illness (a cold) or a gastrointestinal illness (diarrhoea). The way the virus spreads between hosts depends on the illness it causes. Viruses that cause respiratory illness will spread via coughs and sneezes in the same way that the common cold or flu is spread. Viruses that cause gastrointestinal illness spread via contamination of food and water with faecal matter.

Why is this one different from previous coronaviruses (e.g. SARS/MERS)?

The new coronavirus is different from previously known coronaviruses because it is a new species. It has a different genetic makeup to previously known coronaviruses and will, therefore, behave differently. Precisely how this new coronavirus infects cells, causes illness and spreads is not yet known, but scientists will be working hard to understand that in the future.

Why do different coronaviruses have different severities?

Different coronaviruses cause varying severities of disease for many reasons. The overall outcome of an infection will depend upon how several factors act together. For example, how healthy the person or animal is, whether they have been exposed to a related viruses, how effective the virus is at infecting cells and then replicating, and the viruses’ ability to overcome the immune system.

Is there any treatment or vaccines for coronavirus infections? Are there any for this novel Wuhan coronavirus?

Different members of the coronavirus family infect and cause problems in a variety of animal species. Vaccines are available and used regularly in livestock industries to protect animals such as chickens and pigs against infection with coronaviruses. It is too early for vaccines to have been developed against the new coronavirus circulating currently and there are no licensed coronavirus antivirals. Treatment of patients aims to manage the symptoms of infection so the body can fight the virus. However, scientists around the world are working to understand how this important family of viruses make new copies of themselves inside cells and how they cause disease, which could lead to new vaccines and antivirals in the future.”

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

“It is very difficult to quarantine an entire city. The scale of these public health interventions is unprecedented. It’s a bit like trying to quarantine London or New York. A significant factor into whether the quarantine itself works will be the compliance of the population. In the UK or US, there would have to be real public acceptance that this measure is required. The increased state control in China may increase the compliance and make it logistically easier. But regardless, it’s going to be very difficult to manage.

“There will be challenges around the impact on those people inside of these large quarantine zones. Will they have enough food to eat? How will their health facilities operate? Will people still go to their doctors and hospitals? How are emergency cases going to be treated? Will the hospitals have any medicines left? These are all questions China will be considering right now.”

Prof Robin Shattock, Professor of Mucosal Infection and Immunity, Imperial College London, said:

“The current Coronavirus outbreak in Wuhan again raises the spectre of a respiratory pandemic. While there is no current evidence to suggest events in Wuhan will lead to a pandemic it does raise the question as to how quickly a vaccine could be generated and be in place for first responders in the UK should a pandemic occur. Typically, current cycles of getting a vaccine into humans studies is 1-2 years from sequence identification. However, response to any pandemic threat ideally needs to be within months rather than years. By using novel synthetic RNA vaccine technology, modelling suggests this could reach clinical testing within a few months. This has not previously been achieved for any virus but could be tested if a “live fire exercise” were to be rapidly funded. However, there is always a tension in responding too rapidly to an event that doesn’t occur against holding back and being too slow to respond after an event has become a serious threat”.

Prof Jonathan Ball, Professor of Molecular Virology, University of Nottingham, said:

“It’s reassuring to see that travellers who have visited Wuhan, and who are now experiencing respiratory symptoms, have sought medical help. The individuals are isolated, and the diagnostic lab will now be testing to see if they have evidence of the novel coronavirus. If they have, then they will be given appropriate medical care and the people that they have been in contact with traced and monitored to ensure that they haven’t contracted the virus too. It’s by using these well-established tried and tested measures that we deal with these exotic outbreaks as and when they happen. Of course, it is more likely that they are suffering the ill-effects of many of the other cold and flu-like viruses that do the rounds in winter, in which case, provided their symptoms allow, they can carry on to their intended final destination.”

Prof Paul Hunter, Professor in Medicine, The Norwich Medical School, University of East Anglia, said:

On how this outbreak compares to the SARS outbreak response:

“The first case of SARS (Severe Acute Respiratory Syndrome) was first identified in November 2002 in Guangdong Province, China. From 1 November 2002 to 31 July 2003 there were some 8300 reported cases and 775 deaths. Case numbers started to increase throughout December and January increasing more rapidly during the last week of January first week of February 2003.  After a short-lived decline case numbers increased dramatically during March and April before eventually stopping in July of that year. That there may be a problem with an acute respiratory illness was first detected in the west late November and early December. The World Health Organization wrote to the Chinese authorities twice in the first two weeks of December to ask for further information but the reply from China apparently only concerned data on influenza cases. It was not until the 10^th February that WHO was notified by the Chinese of 300 cases and 5 deaths in an outbreak of acute respiratory syndrome. WHO issues a global alert on March 20^th after it had spread internationally. It was not until April that the virus responsible was finally identified.

“By contrast in the current outbreak the first four cases were admitted to hospital on the 29^th December 2019. At that time the causative virus was not known but it was noted that all 4 had worked in the Huanan Seafood Wholesale Market.  The following day these cases were widely reported by the Chinese authorities. On the 8^th January it was officially reported that the cause was a novel Coronavirus.

“Since the SARS epidemic in 2002-2003 the response of the Chinese authorities has been very different. The authorities have been much more open about the outbreak, investigated the infection much more rapidly and thoroughly and shared that information with the international community. The authorities have also initiated very strong control measures in affected cities. The causative virus was also identified substantially earlier in this epidemic. As a result of this increased openness and better management in neighbouring countries should be able to prepare well in advance of any cases that may arrive on their shores.”

On the source of the virus:

“It is still not known with certainty and it may never be definitively proved. There are initial, although contested, reports that the virus has already been detected in both bats and snakes and the strains in both bats and snakes are similar to each other and to the strains from human cases. All the work around this new outbreak is new and ongoing which can explain why there are differing thoughts on what the source may be. There is still much more to find out about the virus and there is a real possibility that the exact origin may not be found.”

“What has been happening already is that people have been comparing the gene sequences with those reported by scientists looking at viruses in animals (see previous answer). This is probably as good evidence as we will get. Ideally we would like to isolate the virus from food animals in the market but it is likely that the infected batch of animals are long gone. However, the big question is no longer where it came from but how and where it is spreading in human populations.

 “Any cooked food is unlikely to be the source. I suspect the most likely transmission pathway would be from aerosols produced during handing of the live animals and during butchery and food preparation which would then be inhaled or contaminate surfaces which would then be touched by people. However, raw food is also a risk.

Possible impact of the virus:

“A typical influenza epidemic can kill many tens of thousands and sometimes hundreds of thousands of people.  Previous novel coronavirus outbreaks have caused the death of substantially fewer people (SARS killed about 800 people globally and MERS about 850). This new strain seems to be rather less lethal than the previous two outbreaks however, this could still change. All new outbreaks are worrying especially in the early weeks when it is not clear how the outbreak could progress. I think it unlikely that the Wuhan coronavirus will be cause a major public health issue in the UK in large part because of our existing health system.

“If the outbreak developed into a pandemic with very large number of cases then it would be a very serious issue for us all. However, I doubt that this will happen, though we still do need to take the outbreak seriously and monitor the situation carefully.”

Prof Diana Bell, from UEA’s School of Biological Sciences, said:

“SARS occurred over 15 years ago and it was the first global pandemic of the 21^st century.

“At the Royal Society’s international conference on ‘Lessons from SARS’ we emphasised that wildlife trade is a major dual threat to human health and a primary cause of biodiversity decline in China and South East Asia.

“But these warnings were not heeded so here we are yet again. Now it’s time for real change and collective action to stop illegal trade in wild animals, their continuing open sale in markets across the region which mix a vast array of species and of course the pathogens they carry”.

“We cannot continue watching Russian roulette with zoonotic viruses and their known potential for causing global pandemics being repeatedly played in this way.”

“What is important now is that the Chinese authorities that cleared and disinfected the affected Wuhan wet market(s) release a list of all the animal species present (or available from stall holders), as well as the results of the disease screening that they will have done on these animals.”

“We also need market workers to provide details about where their animals were sourced from – for example from other animal traders or ‘wildlife farms’ – in order to determine the trade route chain.

“Wild rodents, which are commonly present in these markets, should also have been collected – as rats were shown to carry SARS-like viruses during the previous epidemic.

“It is also important to understand that wild animals are typically now more expensive than domestic livestock so the demand which perpetuates wildlife trade in the region is a dietary choice and not driven by low income.”

“We need to know whether the authorities also closed similar markets across China and indeed neighbouring countries as this would be an appropriate immediate response.”

Prof Tom Solomon, Director of the U.K.’s Health Protection Research Unit on emerging infections, University of Liverpool, said:

“The Chinese plan is to contain the novel coronavirus by stopping all public transport in Wuhan including transport from the city, is understandable given the circumstances.

“However, in general public health officials tend to avoid this kind of response, because it can sometimes be counter-productive. It can increase the level of panic, and just cause people to flee by other means.

“It will be interesting to see whether this isolation attempt is effective.

“There are some historical precedents. In the Middle Ages, some villages affected by plague would isolate themselves to present prevent its spread. Eyam village in the north of England is a very well-known example of this. They built a village wall and did not leave the village until the outbreak was over. 

“The response by Public Health England to set up screening for people with fever and to give out information to travellers from Wuhan is a very sensible and measured response.”

Wednesday 22 January

Prof Paul Hunter, Professor in Medicine, Norwich Medical School, University of East Anglia, said:

“Public Health England and the Department of Health and Social Care announced today steps that is was taking to monitor incoming flights from Wuhan for people who may be infected by the Novel coronavirus.

“These measures including meeting lights from Wuhan and asking passengers about the presence of any symptoms that may indicate a coronavirus.

“Such screen is an important step towards reducing the risk of importation of the novel coronavirus.  However, it is important to remember that screening arriving passengers by itself is not likely to be a very effective control measure. In the SARS epidemic almost 20 years ago, airport screening did not detect a single case looking at data from Australia, Canada and Singapore^[1]. Any detections were false alarms. Even using fever detection equipment would not increase the effectiveness of screening.

“There are several reasons why a real case may not be detected, the person may be incubating the infection and not yet ill, they may be taking medication that supresses any fever or they may not be honest in replying to questions. However, anybody who was obviously quite poorly should be identifiable to ground medical staff and cabin crew. On the other hand the disruption caused to passengers who may have other febrile illnesses can be substantial.

“Public Health England have judged that the risk to the UK from this novel coronavirus is low and I agree with this. The important factors in controlling any new coronavirus is rapid diagnosis of people with illness, referral to hospital and nursing with appropriate infection prevention measures.

“The real value of such screening, however, is as an opportunity to educate arriving passengers about the risks and the importance of seeking medical attention early. Such people will better know how the importance of seeking medical attention sooner rather than later.

[1] Mouchtouri VA, Christoforidou EP, Menel Lemos C, Fanos M, Rexroth U, Grote U, Belfroid E, Swaan C, Hadjichristodoulou C. Exit and Entry Screening Practices for Infectious Diseases among Travelers at Points of Entry: Looking for Evidence on Public Health Impact. International journal of environmental research and public health. 2019 Jan;16(23):4638.

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

“The principles of screening arriving travellers from affected areas largely involves Public Health England being aware of which travellers have arrived from affected regions and then screening them for any symptoms that might be consistent with the 2019-nCoV virus infection. If a person does not have any symptoms they will be free to leave the airport but will be provided with information of who to contact if they become unwell and to inform healthcare professionals of their travel history. PHE may also retain contact details for these people in order to contact them later on if felt necessary.

“It is wise to implement checks at this stage given the evidence on increasing spread of the virus to other countries and across continents, but largely for the purpose of being in contact with travellers from affected regions in case they become unwell. If they were to be unwell at the airport or become unwell in the future it will allow more prompt isolation and testing of the patient, with appropriate tracing of any people the patient may have been in contact with. This will hopefully limit the amount of people the person may have contact with while unwell and so limit the spread of the virus. Screening for symptoms at airports is limited as it will only identify people who have symptoms at the point they transit through the airport. Some people may not have symptoms at this point, but might develop them later on, it is therefore important that PHE are able to trace them in the future to determine if they have gone on to develop any symptoms.”

Tuesday 21 Jaunary

Dr Andrew Freedman, Reader in Infectious Diseases / Hon. Consultant Physician, Cardiff University, said:

“This first case to be identified outside of Asia is a worrying but not unexpected development.  It is likely that further cases will be seen in other countries around the world, including the UK and Europe, in the days & weeks to come.  Although person to person spread of the virus has occurred, including from patients to healthcare workers, it is not clear just how contagious it is.  This is important in determining the risk of a much larger outbreak developing with spread to people who have not travelled to Wuhan.

“It is likely that the US and other countries will be considering what further measures are needed to limit the risk of more cases arriving from China. The WHO is monitoring the situation closely and may decide to declare an international public health emergency.”

Prof Mark Woolhouse, Professor of Infectious Disease Epidemiology, University of Edinburgh, said:

“It is no surprise that a case of Wuhan coronavirus infection has been found in a traveller to the United States, but it does increase the likelihood that the World Health Organisation will declare this to be a Public Health Emergency of International Concern. There is every likelihood that other cases will be imported into other countries in the coming days and weeks. The next stage to watch out for is whether there is any evidence of transmission outside China. This has not happened yet, but it would be an important development. While this outbreak is a becoming a major public health concern it is important to stress that, though similar, it is not as severe an infection as its predecessor, the SARS coronavirus.”

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

“While the detection of 2019 nCoV (Wuhan Coronavirus) in an unwell patient in the US causes increased concern, it is not surprising as we are aware that the virus can spread from person to person and that there has already been detection of the virus in patients who have travelled from Wuhan back to Thailand, South Korea and Japan. Given our increasingly inter-connected world and the frequency of international flights, the potential for the virus to spread to different continents was and is high. This report will likely impact on the decision made the by the WHO International Health Regulations Emergency Committee who will be meeting tomorrow to discuss whether the situation constitutes a Public Health Emergency of International Concern.”

Prof Jonathan Ball, Professor of Molecular Virology, University of Nottingham, said:

“For a virus outbreak that was identified around a month ago, the number of exported cases and the recent uplift of numbers is concerning; particularly as the suspected source of the outbreak – a fish market that supposedly also traded in live animals – has been closed for some time.

“This, together with reported chains of human to human transmission means this is an outbreak that the international community needs to take seriously.

“We need to identify the source and determine the level of community infection and spread – only then can this be brought under control.”

Prof David Heymann, Professor of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine (LSHTM), said:

“Continued reporting of information about persons infected and their clinical outcome from China and countries to which the virus travels will permit a full risk analysis by the WHO. It is known that the virus passes from person to person – more evidence will help determine if it spreads through the air as did SARS, or through close human to human contact as does the MERS coronavirus. It will also indicate the number of hospital workers infected and the extent to which they may have inadvertently caused other infections in patients hospitalised for other reasons and to their families and communities. Finally information about who is at risk of serious disease and death will indicate whether the risk is to all ages as was with SARS or mostly in the elderly with co-morbidities such as diabetes or chronic lung disease.”

Prof Paul Hunter, Professor in Medicine, Norwich Medical School, University of East Anglia, said: 

“The report of a case of the Wuhan coronavirus in the US indicates that this person probably acquired his infection in the Wuhan region and so fits with the current picture of the epidemic. If this is the case then the potential for further spread in the US is low. Far more important has been the recent reports of person to person spread in China. As yet there have been few reports of person to person transmission compared to the total number of cases which would suggest that the outbreak will burn itself out quite quickly. However, the ability of a novel virus to spread person to person may increase through evolution as it spreads. In such a scenario then the potential for a major global epidemic as previously seen with both SARS and MERS-CoV remains.

“During the SARS epidemic in 2002-2003 there were 251 cases and 44 deaths in Canada Many of the cases in Toronto were associated with a local hospital and occurred after infection control prevention measures were relaxed. Providing infected patients are identified quickly and nursed in appropriate facilities then the potential for spread within developed nations should be low.  However, should infection control procedures not be rigorously enforced then subsequent spread may occur with potentially serious impacts on public health.”

Dr Jeremy Farrar, Director Wellcome, said:

“This outbreak is extremely concerning. Person to person transmission has been confirmed and, as expected, we are seeing rapidly increasing case numbers across China, and in more countries, with health care workers infected. The World Health Organisation’s role is to ensure the global public health response to any new outbreak is rapid, robust and comprehensive. Given the geographic spread of cases, calling the emergency committee to consider whether to declare an international public health emergency should now be a part of this process.

 “The speed with which this virus has been identified is testament to changes in public health in China since SARS and strong global coordination through the WHO. However, we know there is more to come from this outbreak – and with travel being a huge part of the fast approaching Chinese New Year, it is right that concern levels are at the highest level.

 “A major concern is the range of severity of symptoms this virus is causing. It is clear some people are being affected and are infectious while experiencing only very mild symptoms or possibly without experiencing symptoms at all (asymptomatic). This may be masking the true numbers infected and the extent of person to person transmission.  It is a matter of urgency to work this out.

“The world is much better prepared to identify patients and take the necessary public health and clinical measures, than it was during SARs, nearly two decades ago. However, we still do not understand this virus or the public health and clinical impact. The urgent focus must be on evidence-based interventions. We also do not have proven treatments or vaccines. CEPI (the Coalition for Epidemic Preparedness Innovations), which Wellcome supports, is now working with global partners to accelerate vaccine research for this new virus.”

 Monday 20 January

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

“There is not much information on the symptoms the British tourist is suffering from in Thailand in current reporting in the media. It is also unclear if he has had any contact with any confirmed cases of the Wuhan coronavirus. That he has a potential lung infection and a collapsed lung could be consistent with what we know so far of Wuhan Coronavirus, but it could also be consistent with many other respiratory infections, both bacterial and viral. If the patient has had known contact with a case of Wuhan coronavirus or has travelled to China in the last few weeks it is prudent to consider this in the differential diagnosis, while also screening for other viruses and bacteria that may cause such symptoms.

“The virus is currently identified using a real time polymerase chain reaction (RT-PCR), this identifies the viral RNA in the biological sample from the patient, which could be a throat swab, a cough sample or possibly a blood sample if the patient is very unwell.

“The UK population currently is not exposed to the virus as there have not been any confirmed cases in the UK at present. However there is potential for exposure given the volume and frequency of international air travel and the potential for someone travelling from an affected region arriving in the UK prior to them developing symptoms. This is where appropriate screening measures need to be in place for travellers from affected regions who become unwell with fever and respiratory symptoms. Largely it would be something for a healthcare worker to consider if they had someone with respiratory symptoms who had history of contact with a confirmed case or travel to an affected region. Airport screening can be limited in its efficacy as it screens for symptoms/fever in people with a travel history to an affected area and is dependent on travellers having symptoms at the time they arrive in the UK/pass through the airport.

“While data is still limited it appears likely that the Wuhan Coronavirus is spread through contact with an infected person’s secretions and respiratory droplet infection, this is contact with small particles in the air that occur when an infected person coughs or sneezes. This is similar to how influenza virus is spread.”

In response to reports in the media that a British man in Thailand has symptoms similar to the Wuhan coronavirus: Prof John Edmunds, Professor in the Centre for the Mathematical Modelling of Infectious Diseases, London School of Hygiene & Tropical Medicine (LSHTM), said:

“Whilst there have been two cases that have travelled to Thailand from Wuhan, there is no evidence of any transmission of this virus in Thailand as yet. Hence, although it is possible that this is a case of the novel coronavirus, it would seem very unlikely.”

 Saturday 18 January

Dr Mike Turner, Director of Science, Wellcome Trust, said:

“We are in the early stages of this outbreak. There has been some excellent and very speedy work by authorities in China and the research results have been made available to the world very rapidly indeed. This is making it easier to monitor the spread of the disease. Despite which, estimates of the size of any outbreak are very difficult to predict at this early stage but it is clearly still spreading. We are all more concerned than we were three days ago. One of the consequences of a more connected world is that outbreaks have to potential to spread internationally much more rapidly than was the case 50 years ago. Whether health screening at airports makes a useful contribution to reducing spread is a moot point.”

Dr Jeremy Farrar, Director of Wellcome said:

“Uncertainty and gaps remain, but it’s clear that there is some level of person to person transmission. We are starting to hear of more cases in China and other countries and it is likely, as this modelling shows, that there will be many more cases, in a number of countries. The speed with which this virus has been identified and the sharing of that information by China, has been amazing, a testament to the changes in public health in China since SARS and the global coordination through the World Health Organisation.  That has meant that the world is much more prepared to identify patients and take the necessary public health and clinical measures than it was even a week ago.

“It is possible that the often mild symptoms, and probability of people being affected and infectious without experiencing symptoms (asymptomatic), from this coronavirus may be masking the true numbers of people who have been infected, and the extent of person to person transmission. It is also probable that we are looking at patients being affected over a number of days from multiple animal sources and with some degree of human to human transmission.

“The speed of response is testimony to improved global preparedness. But we must not be complacent, there is still much to be done to ensure countries across the world are protecting people from epidemic threats of diseases known and unknown.

“Ongoing research, with continued prompt and full data sharing, is vital to ensuring the correct response to this outbreak. Wuhan is a major hub and with travel being a huge part of the fast approaching Chinese New Year, the concern level must remain high. There is more to come from this epidemic.”

Declared interests

None received.