We have to respect the coronavirus – and learn as the disease evolves
At the end of February, the WHO's assistant director general Bruce Aylward set out to learn more about China's response to the covid-19 outbreak. He tells New Scientist what he thinks the rest of the world can learn from China's approach
Xing Guangli/Xinhua News Agency/PA Images
Epidemiologist Bruce Aylward is assistant director general of the World Health Organization and spoke to New Scientist on 13 March. This interview has been edited for length and clarity.
New Scientist: Cases in China are declining – we are now only seeing a handful of new reported cases every day. Does China have the virus under control?
Bruce Aylward: They have absolutely turned it around. The trends are very real, there’s no question. Governors, mayors and others that I talked to in China would never say things were “under control”. When I asked them if they felt good about falling cases, they said no. They said they were building more beds and buying more ventilators, because they were worried that they might never get something like this – a new virus that we don’t understand – under control.
Now they are planning to open up all of the travel restrictions, get people back to work and get students back to school. But their feeling was that this is going to remain in the population and raise its ugly head, and they have to be able to respond rapidly.
How did China get to this point?
China did something that most other countries would not even have tried, and many people thought would have been impossible. They used fundamental public health approaches – such as case finding and contact tracing – to stop a respiratory virus.
That seemed almost impossible as a premise because respiratory viruses transmit so effectively and efficiently – typically the only way you can stop them is with a vaccine or pharmaceutical treatment. What China did provides a lesson for infectious disease epidemiologists.
Does that mean China has taken the model approach? Were those lockdowns that seemed so extreme at the beginning the right way to go?
Everyone always starts at the wrong end of the China response. The first thing they did was to try to prevent the spread as much as they could, and make sure people knew about the disease and how to get tested.
To actually stop the virus, they had to do rapid testing of any suspect case, immediate isolation of anyone who was a confirmed or suspected case, and then quarantine the close contacts for 14 days so that they could figure out if any of them were infected. Those were the measures that stopped transmission in China, not the big travel restrictions and lockdowns.
Stopping the movement of people doesn’t stop the virus jumping from person to person, it just prevents those people from moving to other places. The travel restrictions and lockdowns were to give them time to get the other things in place and actually stop transmission.
When I spoke to Italy the other day, they said: “We’ve got these lockdowns in place.” I said: “Great, you’ve done the hard part, now you have to do the really hard part, and that is making sure the cases are effectively isolated.”
Italy is the most affected country in Europe. What’s happening there?
What’s happening in Italy, and in many other countries in Europe, is that they’re treating the mild cases at home. In some countries they’re not even testing them. They are saying if you have a cough and high fever, stay at home. But the problem then is that they don’t know that they have the disease, they haven’t had it confirmed. After a couple of days people get bored, go out for a walk and go shopping and get other people infected. If you know you’re infected you’re more likely to isolate yourself.
Generally in a population, around 60 to 80 per cent of those affected are going to have mild or moderate disease. If those people are all out of hospital, most of your cases are at home, but not isolated. In China, they found that didn’t work. They had to get them isolated in hospitals or dormitories or stadiums. The main goal was to keep them from getting bored.
Which countries have responded well to the outbreak?
There are lots. Look at South Korea – they have been pretty rigorous about testing all the suspect cases and finding all the contacts. In the past couple of days, we have seen that, instead of that relentless upward creep in cases, they seem to have turned a corner, which is positive.
Singapore is another country that has been hit with importations again and again, and they are jumping on them, tracing all the cases, tracing all the contacts, professionally isolating them all. They seem to be doing pretty well, even though they have got relatively big numbers.
Canada had importations into four or five different provinces. And in almost all of those they have been able to keep the numbers fairly low, following a very similar rapid test approach. And in all those places, it’s very easy to get tested as well.
Do you think these countries have learned lessons from other, past outbreaks?
Oh absolutely. When you look at Singapore, South Korea, China – why are they so aggressive in terms of case finding and contact tracing for coronavirus? Well they were all hit by SARS. Similarly, if you look at Canada, they had a big SARS outbreak back in 2003, with hundreds of cases.
They saw the devastation a coronavirus can cause, and they were serious about it – they jumped right on it.
Why has the case fatality rate been lower in South Korea than other countries?
They have a relatively young population. The population aged over 65 in South Korea is something like 14 per cent – half that of Japan, and much lower than Italy. A case fatality rate of around 1 per cent – close to what we are seeing in South Korea now – is what we see in a young population. Younger people just have a lower mortality rate.
But the case fatality rate has been creeping up over time. The thing that I would remember, even right now in South Korea, is that [the fatality rate] is still tenfold higher than seasonal flu.
Is that why it has been so bad in Italy, because the population is older?
We are not sure. I saw some data from the north [of Italy] that suggests around one-third of cases are being managed at home. That means they still have a lot of mild cases that may not be diagnosed. Because they have so much work taking care of the sick people, some of the milder cases just aren’t being tested and officially diagnosed. That’s part of the problem.
The second is the older population. The third is they are also very early in the outbreak, and that can sometimes be where you see higher mortality among older people, and it distorts the picture.
Why do you see more deaths at the beginning of an outbreak?
Often it’s a reporting artefact, combined with the fact that older people will unfortunately die earlier. People with cardiovascular disease, heart disease and so on have a much higher fatality rate. As soon as they get an acute infection, and they get into respiratory distress, they can’t get enough oxygen into their blood and they can die very quickly.
What’s happening with the younger people is different. In the initial infection, they don’t do so badly – they feel fine, basically. But then over a couple of weeks, they [may] get an inflammatory process in their lungs – the true disease of covid-19 – and they cannot get enough oxygen into their lungs, and they end up on ventilators. They may get better, they may die. But that can take three to four weeks. So at the beginning you are looking mainly at the phenomena related to the older people. And then as time goes by you will see more of a problem in the younger population.
What about the UK, which isn’t taking as strong measures as some countries?
People have different reasons for taking different measures at different times in an outbreak. Chris [Whitty, chief medical adviser to the UK] is one of the brightest, most sensible and careful people I know. I’m not going to second-guess anybody at this time.
Are there any countries you are particularly worried about?
We are worried about everywhere. When declaring a pandemic, part of what the director general of the WHO was saying was: look, we have seen this virus cause explosive outbreaks in multiple continents now. We have seen it cause this societal and economic damage in multiple different settings.
The reality is we are worried about everywhere right now because we did not think the world was ready. Countries may be ready in that they can do surveillance and test lots of people. But do you have enough beds? Do you have enough people to find the cases and to find the contacts?
The place I would be least concerned about right now is China, because it’s the only country that has shown it can really deal with this at scale. The countries that we really worry about are the low capacity countries in the south – in Africa, parts of Latin America, parts of South-East Asia – where we have not seen the big numbers yet. We are really worried about the kind of damage it could do if it takes off in those places.
Why do you think we haven’t seen big outbreaks in those areas?
Part of it is simply time. Another possibility – although now we are speculating – is the possibility that it will pick up with the flu season in Africa, which is not for a few months. We simply don’t have a clear answer.
Plenty of strategies have been used to contain the virus. Does testing people’s temperature at airports work?
If you look at the data, not very many cases have actually been found and prevented [this way]. But it is important to raise population awareness of diseases. And there’s nothing like thermal scanners to do that.
The other thing people say, which we cannot measure, is that they act as a deterrent. People who do have a fever and do feel unwell, they say, you know what, I would rather stay at home than get stuck in quarantine or some mess in an airport somewhere, and they don’t travel, because they will be screened.
What about closing schools?
That’s a tough one. Here, the data historically have been a lot stronger, but it’s for a different disease – it’s for flu. Kids get these rip-roaring flus, and the whole classroom gets sick. The kids get their families infected. Parents have to stay at home with the kids, and then they get sick, go to work and infect others.
But one of the curious things with this disease is that we have not seen school outbreaks. I talked to my colleagues in South Korea, in China, in Italy, everywhere – no one has seen school outbreaks. They have seen situations where a teacher is infected and they have infected kids, but that is different to the kids all getting each other infected.
When you talk about school closures, you want to know, is it going to reduce the intensity of transmission? We know that it probably won’t reduce the number of sick people very much, because not many kids get sick. But what we don’t know is, are kids getting infected and we just can’t see it? And if they are, are they carrying it back to their families? Even there we don’t have a lot of data to suggest that kids are infecting their families. So as a result, countries have done things differently.
It must be difficult to balance public health and the economic impact of such measures.
This is the kind of thing that can just drive a country back into a recession. And for China, this was a major issue. Chinese officials said their number one priority was to save lives. But then they said to save lives, our economy has to work as well. And even before they had gotten close to zero cases, they were already trying to get people back to work, get key industries reopened and do it as safely as possible.
There’s a chance that when cases decline and restrictions loosen, we’ll see more infections. What happens then?
China decided that they cannot afford to wait for cases to go to absolute zero – not knowing if they ever will – so they decided to strengthen their whole system so that they could live with the disease if they had to. They are building additional capacity to isolate people, and they are building additional ventilators. They are planning to be able to manage low-level disease and prevent large outbreaks. It’s a very sensible way to plan, especially when you see something as devastating as this.
It’s wishful thinking to think that the virus is going to disappear altogether. People keep saying that maybe in the warm season it will. Last time I checked, Singapore was very, very warm, and it’s roaring away there.
Should other countries be increasing the capacity of their healthcare systems?
Absolutely. Not just their health system, but also their public health system, which is often a separate thing. The people who do the case finding, the investigations, the contact tracing – that’s your public health system, and that often is the very poor cousin to your health system. The reality is that the health system deals with the consequences. The public health system is the one that prevents the consequences from getting so big.
Have you seen anything like this outbreak before?
There’s lots of different things you can compare it to, and say, “it’s a bit of this and a bit of that”. But as soon as you [compare the disease to others], you are dead. This is a new disease. Respect it and learn as it evolves. The more you lean on your old [experiences], the more mistakes you are going to make.
Read more: https://www.newscientist.com/article/2237493-we-have-to-respect-the-coronavirus-and-learn-as-the-disease-evolves/#ixzz6HKMgob8f
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