Coronavirus Outbreak: Why the Risk Is Higher for Older People With Pre-existing Conditions

As China clamps down on travel in and out of Wuhan and 12 other cities where a new global health threat is emerging, Canada has recorded its first case of coronavirus in Toronto.

Health officials continue to remind Canadians that the risk of contracting the virus is low.

 

The coronavirus – named for spikes on its surface that resemble a crown — is officially called 2019-nCoV and is similar to SARS (severe acute respiratory syndrome), which spread across the globe in 2003. That virus also originated in China in a catlike animal called a civet before it jumped to humans. It spread to 29 countries, infecting about 8,000 and killing almost 800. Toronto became the epicentre of the outbreak in Canada, where 443 people were infected and 44 died.

The World Health Organization (WHO) decided not to declare a global emergency on Thursday afternoon.

“I wish to reiterate that the fact I am not declaring a Public Health Emergency of International Concern today should not be taken as a sign that WHO does not think the situation is serious or that we are not taking it seriously,”  WHO’s director-general Dr. Tedros Adhanom Ghebreyesus said at a news conference in Geneva.

“WHO is following this outbreak every minute of every day, at a country, regional and global level. We are working to prevent human-to-human transmission.”

He said China is sequencing the genome of the coronavirus, and the WHO is working on diagnostics, therapeutics and vaccines. “We are committed to ending this outbreak as soon as possible.”

 

Cases began to appear in late December in the port city of Wuhan, centred around the Huanan Seafood Market, which also sells wild animals. As of Friday, there were more than 800 confirmed cases and 25 people have died in central China. The first death outside the city of Wuhan was confirmed Thursday, that of an 80-year-old man who had lived in Wuhan for two months before travelling to his home 1,000 kilometres north of the epicentre of the outbreak in Wuhan.

People with the infection have also been reported in Thailand, South Korea, Japan, Vietnam, Singapore and the U.S., which confirmed its first case on Tuesday. That patient is in isolation at Providence Regional Medical Center in Everett, Wash. He is in his 30s and lives in Snohomish County, Wash., just north of Seattle. He had recently returned from Wuhan.

“I think it’s important that we’re not alarmist, but that we’re cautious and we’re prudent, and that’s exactly what Canada is doing,” federal Health Minister Patty Hajdu said Thursday.

Health Canada says coronaviruses usually cause colds, and anyone experiencing symptoms such as fever, headache, runny nose, cough and difficulty breathing should stay home, cover their noses and mouths when coughing and sneezing, wash their hands and avoid close contact with others. Those who have travelled from China and think they may have been infected are being asked to report to a health-care professional.

The majority of patients who have died were elderly and suffering from pre-existing conditions, including the latest victim in Hubei, who was also treated for high blood pressure, chronic bronchitis and emphysema.

We talked to Dawn Bowdish, the Canada Research Chair in Aging and Immunity at McMaster University in Hamilton, about coronavirus, why the elderly are more likely to die from it and what we’ve learned since the SARS epidemic of 2003.

What is the coronavirus?

It’s a family of viruses that includes the viruses that cause SARS. They tend to be quite deadly. They tend to arise from wild animals. One of the reasons China is a hotbed of these entering into the human population is because they have a lot of animal markets that have live animals. Whereas in North America we tend to slaughter them at the farm and then we buy most of our meat frozen and, even if it’s fresh, it’s not alive in our grocery store. In China, there’s a very different model where people actually buy fresh – I believe they call it “warm meat” – they want it freshly slaughtered. So there are a lot of possibilities for contact between humans and wild animals. These viruses tend to live a lot more in wild animals and, very rarely, they can cross over and make a human sick.

But that has happened.

It has happened. So this is very much the story of SARS all over again. But fortunately the world has learned a few lessons since then, so the response has been very, very different. Where the real danger comes is if the virus acquires mutations that allow it to spread from person to person. That is what’s happened here. So if, say, market workers start getting sick but it never spreads, then you can contain that. The issue is if the virus gets into the lungs of a person and the sick person coughs or sneezes and transmits it to the next person. That’s when things start to get a little bit scary.

Risk Increases With Age

Why do older adults get sicker?

There’s a bunch of risk factors. They could have pre-existing co-morbidities. So anyone who has got lung disease is at very high risk. People who have Type 2 diabetes are always more susceptible to infection, especially lung infections. Or there may be other health concerns.

Why Type 2 diabetes?

Type 2 diabetes causes your white blood cells to function less effectively. We call it immunometabolism. So there’s a real link between the immune system and the metabolic system and older adults are at increased risk for Type 2 diabetes or have pre-diabetes.

Is it fair to say that pre-existing conditions tax our immune system so it’s not as strong and able to fight these viruses?

Yes. And especially lung conditions. If your lungs aren’t able to flex, say if you have lung fibrosis or COPD, and your lungs aren’t very good at their job of moving, then that makes it harder to get oxygen in. And if your lungs are already filled with fluid, then it’s a real problem because they have to work that much harder. Similarly, when you have trouble breathing, it’s very hard for your heart. So people who have pre-existing heart conditions really struggle when they have pneumonia because the amount of energy they need to keep their heart pumping, and breathing is already pretty high.

And our immunity naturally wanes as we age. Is that also a part of the increased mortality risk?

Absolutely. Older adults tend to have higher amounts of the virus because they can’t get rid of it as much, and it tends to infiltrate deep into their lungs. Without a really robust immune system, it’s really challenging.

Lessons From SARS

How will the response to this epidemic be different from SARS?

First of all, China’s been much more forthright about sharing data and about being proactive. Imagine. if you will, somebody comes to your hospital with a fever. You’re never going to panic because the most common reason is influenza, and all these things that humans get — it’s very rare to be an emerging virus like this. But with the initial patients, their fevers were high, and it looked a little bit suspicious and health-care workers were very proactive and identified the type of virus it was first and then they released the DNA sequence quickly so that people could create tests to detect it.

The second big issue is that China has remarkably closed down cities — and during the Lunar New Year, which is the most important holiday of the year where people travel to see their families. They’ve been extremely proactive.

Airports are also being very proactive about screening people from that area of the world and looking for fevers. What we need is a Star Trek Tricorder to tell us what people have, but all we have right now is a thermometer. But people are being very proactive about looking at that part of the world and isolating people. The challenge is that we are often sick before we have symptoms. So people get on that plane and they feel fine and they get off and then they have a fever.

Does everyone have a detection test now? It’s been reported that Russia has one.

Counties are working frantically. It’s one thing to make one of these tests, but it’s quite another thing to prove that it works. I don’t think it will take public health authorities very long to develop something.

What’s the incubation period?

I think three days is the predicted time.

So you could be sick but not have symptoms for maybe three days.

Yes. Some airports are screening people getting on the plane, but we have to make sure we’re screening when they get off, too. Having said that though, all the travel outside the three most highly affected cities [in China] has been shut down, so hopefully there will be a quick end.

Take Precautions

The WHO did not declare this a global emergency. What should we do?

Don’t travel to affected parts of the world. And as of right now, it’s really not a threat to anyone who’s not travelling to that part of the world. If, hypothetically, you had contact with someone who’d come from that part of the world or someone who is known to be infected and you develop a high fever, you should certainly go and tell a health professional. But the risk to anyone who has not come in contact or been to that part of the world is very, very low.

So I’m getting on a plane later today. I’m not going to China but I’m going to be at an international airport. What precautions should I take?

I travel a lot, too. And I get sick every time I’m on a plane because of the dry air, so I’m very sympathetic. You could wear a face mask. However, the cheap ones that you buy are not as effective as you’d want them to be. Don’t touch your face. Wash your hands. Don’t go anywhere where people are sick.

In truth, in North America what we have to worry about more is influenza, not SARS. But don’t go anywhere if you’re sick. Don’t let your friends and family go to work when they’re sick. Those are the best practices. And get your flu shot because in our country, influenza is going to cause more deaths than the coronavirus ever will.

Speaking of vaccination, will vaccines be developed for this virus?

Sure. One of our best-case success stories for getting a vaccine made quickly came from the Ebola outbreak. We went from having tens of thousands of people being sick to quickly using pre-existing research and technology and getting a vaccine that works.

Unfortunately this family of viruses seems to be evading our ability to make good vaccines. Researchers are actively studying this family of coronaviruses but we don’t have anything after the research stage right now. But as these outbreaks become more and more common, there’s more money going into funding the research so we can be prepared for the next big pandemic.

And the SARS outbreak would have been the impetus?

Absolutely. We’re very interested in this collection of viruses because they seem to have such a huge potential. SARS was 2003, and this is like a blink of an evolutionary eye. So does this mean that every dozen or so years, we are going to be having one of these outbreaks? We had a MERS (Middle East Respiratory Syndrome) outbreak in the interim, so clearly this is going to keep happening, and it has definitely stimulated research in the area to develop strategies to keep us healthy.

What are those strategies, specifically for the older population?

The best advice always is if you have chronic health conditions, keep them managed. People, like I said, who have Type 2 diabetes are more likely to be infected. But people who have well-managed disease – they keep their blood sugars stable – are always better off.

Similarly, for people who have heart disease, keeping it well managed with exercise and healthy eating, that helps. Keeping your muscle mass. Because when you’re sick and you can’t eat, that’s what your body uses as energy. So building muscle helps older adults deal with infections. For this particular virus, stay away [from it] is the best advice.

And I would point out that even though older adults are more susceptible, young people are also getting sick and dying. So everybody needs to practise safety.

This interview has been edited and condensed for length.

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