The Moodie Davitt Briefing: Public health expert Dr. David Heymann on the coronavirus outbreak (Edited highlights only)

INTERNATIONAL. As part of our continuing service to update the travel retail community on the novel coronavirus outbreak and its impact on business, The Moodie Davitt Report today hosted a phone-in audience with Dr. David Heymann, Professor of Infectious Disease Epidemiology at the London School of Hygiene & Tropical Medicine and Head of the Centre on Global Health Security at Chatham House, London.

From 2012 to March 2017, Dr Heymann was chairman of Public Health England. Earlier in his distinguished career, he was Executive Director of the Communicable Diseases Cluster, and crucially, he headed the global response to SARS in 2003.

The Moodie Davitt Report Chairman and Founder Martin Moodie led the Q&A session with Dr. Heymann, covering a wide set of themes designed to bring the travel retail sector the latest facts and insight on the novel coronavirus outbreak and an expert view on what lies ahead. President Dermot Davitt led the Q&A from the industry audience listening in from around the world.

We present edited highlights in this story, with further coverage to follow. A full transcript will be provided tomorrow to all those who dialed in.

Dr. David Heymann: Shared his insights into the spread of the novel coronavirus and what might happen next

Martin Moodie: The World Health Organisation said yesterday that there is a “window of opportunity” to stop the novel coronavirus becoming a broader global crisis. You said this week that it was too early to estimate when the outbreak would peak as it appears to still be on the increase. Could you expand on that?

Dr. David Heymann: There are several factors required to understand this outbreak. That includes the transmissibility – the ability of the virus to spread from person to person; it includes the way the virus is transmitted from person to person and the third factor that is not understood is the severity of the infection.

That data has not come out of China because there is quite a bit of work trying to take care of the number of patients they have.

That information will come out in the next few weeks and at the sites where the virus has been exported. There are 23 countries that have received this virus from patients in China. Nine of those countries have had human to human transmissions so we are beginning to understand better how this virus acts in the population.

[Click on the icons above and below to hear some of the highlights from today’s phone-in]

Martin Moodie: In your expert opinion, how long will the period of new infection increase last? Based on previous cases, when do you think containment can occur?

Dr. David Heymann: It’s important to have the evidence first. What I would say is that it’s not possible to predict right now. As we understand from countries where patients have arrived outside of China, it will be more easy to predict based on epidemiological modelling. What that modelling does is it takes the present information understood about the virus and transmission and makes projections.

Those projections vary depending on what figures are used in the modelling. So it is really not possible at present to predict when this will be. What’s important though is to understand that this is different to the SARS outbreak. That began in 2002 with very few patients or even just one patient who began a chain of transmission which continued until it amplified under a hospital setting where workers were infected and spread it to hospital patients, families and communities.

The current outbreak began with an explosive beginning, from what we understand, with many people infected, each one of them setting off an individual chain of transmission. So that is what we are seeing now: family members in close contact developing the illness.

The coronavirus outbreak has had a severe impact on travel, tourism and travel retail markets, with uncertainty over how long it will last [Picture: Lotte Duty Free]
Martin Moodie: How important is it to compare the two outbreaks? And knowing what we know about SARS in 2002 and 2003, how important are the lessons of SARS in understanding the new coronavirus?

Dr. David Heymann: Initially the data that came out of China suggested they might be similar types of outbreak but that it might be less lethal and more related to the MERS coronavirus which came out of the Middle East. That hasn’t changed since then. It’s understood that this can be transmitted face to face and it can also be transmitted by close body contact or body fluids. It looks more like the MERS coronavirus than the SARS virus at this point in time in regards to mortality.

China is reporting fatal cases from among all the people who are infected and the spectrum of disease appears to be from very mild infection which causes symptoms of common cold, all the way through to pneumonia. If we put this in perspective, now they are reporting around 400 deaths and 20,000 confirmed cases.

In a country the size of China, that’s a small number of cases and deaths compared to the entire population of over a billion people. But it is very important because it’s a new virus among humans and its potential is not yet understood. So the fatalities are occurring but what’s not known is the denominator under those fatalities.

We know that in hospitalised patients around 2% of patients have mortality, but there is a whole spectrum of patients that never get into hospitals and aren’t reported as part of that denominator, which is the part necessary to understand the complete spectrum of disease and its mortality rate.

Martin Moodie: What do you feel about the chances of a vaccination and/or suitable treatment being developed in a timely manner to use against this coronavirus?

Dr. David Heymann: Currently there are some vaccines being developed but they won’t be in time to use in the next few months or so when there might be need of a vaccine. Antivirals are being tested in China, but there’s very little understood about what type of ethical clearance has been done and what the protocol is. I know the WHO is working with them to try to understand what they are doing and they are doing some clinical trials with drugs coming from major pharmaceutical companies. 

Dr. Heymann: “The WHO has made some recommendations and those recommendations were that travel and trade does not need to be affected at this point in time. The private sector not only includes WHO’s recommendations but also other factors such as insurance and factors such as worker safety”

Martin Moodie: Does that mean therefore that this effectively will run its course, whatever that course may be?

Dr. David Heymann: There is a basic approach in containing an outbreak and that’s what’s being done in countries where the virus has landed outside of China. Those countries are tracing all contacts and making sure that those contacts are either remaining at home or in a quarantined facility.

Temperatures are being checked daily and, should they develop a temperature they are diagnosed. If they are found to be positive for infection they are placed under isolation in hospital.

They are also identifying other patients who might be infected in their countries and they are isolating them as well. So isolation of patients, tracing of contacts and making sure patients are treated properly is a way an outbreak can be stopped. We’ll see whether that’s successful in countries where the virus has landed from China, but it is difficult to understand what’s going on in China because of all the cases and the widespread outbreak.

Martin Moodie: The audience today listening to this call is linked inextricably to the travel and tourism sector. In your view is there a strong argument for curbing travel or even cross border travel by land? Is that an effective measure?

Dr. David Heymann: The WHO has made some recommendations and those recommendations were that travel and trade does not need to be affected at this point in time. That’s a recommendation to countries, but countries will make their own decision as does the private sector.

Countries use information from WHO with their own risk assessment and make their own decisions based on their own risk assessment and needs. The private sector not only includes WHO’s recommendations but also other factors such as insurance and worker safety. These decisions are made by the private sector and there are other influences on them other than just the risk assessment.

We know that temperature screening does not pick up all cases and all infections because people cross the border in their incubation period and develop the disease after they are in the country. We have seen that in many different countries. So although temperature screening might identify a few patients and provide for them an earlier diagnosis and possibly better management of their infection, it’s not a way of stopping the disease from entering your country.

In a country, there must be good disease detection systems which will identify this infection early and diagnose it and take proper precautions. There are other advantages to screening at airports and providing that to all people coming from where the outbreak is occurring, including the information they need to know if they might have developed the disease and where to report if the disease has occurred. So there are many different approaches many countries use and this is a national decision.

It’s important for the tourism and retail industry to understand what happens when there are cases that occur, such as has happened on a couple of cruise ships where there has been a quarantine of those ships. It’s important to take that into the risk assessment. I can’t give a formula but every company in the industry must take into account the risk assessment done by the WHO, the understanding of the virus and where it’s coming from and make decisions based on insurance and other safety precautions required.

Dermot Davitt (leading audience Q&A): What will be the signs that the virus is slowing down its spread? What numbers should we be watching?

Dr. David Heymann: What we are seeing is that it continues to increase, or at least the reports are increasing. That means the Chinese are looking for cases, finding those cases and reporting those cases. It’s very difficult to say when the epidemic will peak in China.

What we need to watch also is what’s happening in the 23 states outside of China where the virus is known to be present. If they are successful in containing the virus and not seeing it spread out of the immediate area where the cases have been imported, that will be a sign that the outbreak can be contained and possibly a pandemic will not occur.

When a new organism emerges from an animal to a human, there are three possible ways it can act. First is by causing disease and spreading further; a good example is rabies. The second is it spreads from person to person through body secretion or close contact and it disappears; this is true with Ebola and Avian Influenza. And then there are viruses that enter the human population and become endemic in those populations; a good example of that is HIV.

What’s important now is to understand the potential of the virus. It appears it may be like the Ebola virus, Avian Influenza virus, like SARS and something which will not become endemic. It’s not yet clear that that’s the case. We have to be watching those places where there is extreme control now because of the small number of cases.

Martin Moodie: Given the spread of infections over the recent weeks, there is a delay between infection and illness and, eventually death. As the virus spreads, are the mortality rates likely to ‘catch up’?

Dr. David Heymann: What is most likely is as the virus continues to spread is that there will be a broader spectrum of disease. Remember the majority of these infections are not lethal. What is not known is how many of these infections are asymptomatic or have very slight symptoms which are similar to a common cold.

It’s important to understand the case definition being used in China. The case definition defines what a case is and permits you to identify cases. Cases that meet the case definition or persons that fit the case definition are called a case. In China, until recently and possibly still, they use pneumonia in their case definition. Pneumonia is a severe form of the disease and probably not occurring in the majority of the patients. But that’s a denominator they are using to calculate their mortality.

Dermot Davitt: When do you think any travel bans can and should be lifted?

Dr. David Heymann: That I can’t predict and I don’t think anybody can. Travel bans occur as a precautionary measure when the organism or disease is not completely understood. With the SARS outbreak, it was understood the transmission was face to face as it appears with this outbreak.

What happened in Hong Kong was that there was an apartment complex where over 200 cases were confirmed. It was not understood why they were occurring and traced back to another case. It was assumed there was another environmental factor in addition to the human to human.

So other countries that were not able to trace back their patients with other patients who had the infection were presumed to have environmental transmission and it was recommended to postpone travel there. As soon as it was understood how transmissions were occurring in Hong Kong, the travel restrictions were lifted. They were precautionary measures as a means to prevent anything that might be in the environment. So that is why travel bans are set in place. As countries understand more about their virus they will reconsider what they are recommending, as will airlines and other companies.

*Click here for our continuing coverage of the impact of the coronavirus outbreak.

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