Over the past year, Angela Cheung, a doctor, senior scientist at the Toronto General Hospital Research Institute, and medical professor at the University of Toronto, has been working with so-called long-haulers: people who’ve continued to experience symptoms of COVID-19 long after their initial diagnosis — some of them for nearly a year. While early research has linked the condition to other chronic illnesses, such as ME/CFS, there is much that isn’t yet known about long-haul COVID-19 and its treatment. TVO.org speaks with Cheung, whose expertise includes the development of evidence-based clinical guidelines and policies, to learn where the research is at — and where it needs to go.
TVO.org: What are you researching, and how did you get into studying long-haulers?
Angela Cheung: Margaret Herridge and I co-lead a [longitudinal] study called CanCOV. This is a multi-centre study across British Columbia, Saskatchewan, Manitoba, Alberta, and Ontario, and we’re hoping to have a Nova Scotia centre as well. We have been recruiting 2,000 patients with COVID-19 across the spectrum of severity of illness. We recruited non-hospitalized patients as well as hospitalized patients. What we proposed was to look at the short- and long-term outcomes up to a year, although we’re going back to see if we can actually follow these patients for up to three years, and we want to look at the outcomes. But we also want to look at what predicts those outcomes. We noticed that some patients, not everyone, have lingering symptoms, and we are going to [the Canadian Institutes of Health Research] with a proposal to do randomized controlled trials of different therapies to see what works better for these patients.
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TVO.org: There doesn’t seem to be a universally agreed-upon medical definition of long-haul COVID-19. How do you define it?
Cheung: I would describe it as lingering symptoms greater than three months. Sometimes, after a really severe illness, people can have some lingering symptoms even after months, but I would actually look at it as after three months. If someone were sick for two weeks, and then they end up in the hospital for another two weeks, that’s a month. Of course, we expect someone not to be totally back to their normal if they just got out of the hospital. I think a better way to define it is looking at lingering symptoms past that point in time.
TVO.org: What is the symptomology of long-haul COVID-19?
Cheung: We find that fatigue is probably the most common complaint — feeling tired. Brain fog is another common complaint. Shortness of breath, especially with exertion, and racing heart rate or palpitations is another common complaint. But there are many symptoms that people can have. I think it depends on the person; the symptoms may be quite different. And some patients actually have lingering symptoms of change in smell and taste.
TVO.org: What causes long-haul COVID-19?
Cheung: The short answer is, we don’t know. The longer answer is that there are many hypotheses, and I actually don’t think we understand it well enough right now. The problem is that the earliest studies are all over the place. Some studies define long-term symptoms as two weeks or more. And some studies are three months or more. So that’s a big difference. And some studies are just looking at the hospitalized group, which would be quite different from people who are not hospitalized. The other issue is that there may be genetic and ethnic and racial differences, too. And we don’t have enough numbers of the different genetic, racial, and ethnic factors to really know what the differences are. There are lots that we need to learn.
That’s why we’re doing the study. Because we need to understand it better. And we need to find solutions for it as well, and that’s why we’re proposing this clinical trial called “Reclaim.”
TVO.org: Given that there isn’t a fixed definition of long-haul COVID-19, do we know how many people get it? What are the challenges in data collection?
Cheung: I don’t think we really have a good handle on the percentage of people having long-haul symptoms. Windsor Regional Health has a project where they are going to be calling everyone who has had had a positive test to see if they still have symptoms afterwards. You need something like that because currently the public-health agencies are not really collecting that data.
TVO.org: What kind of treatments are being researched?
Cheung: Supplements and herbal therapies, medications that we use for post-viral syndromes. Quite a wide variety of things are being used, including Cognitive Behavioral Therapy and physical therapy. Some of them are based on the science of neuroplasticity, and some of it is based on the science of muscle physiology. There are many different types of therapies, and that’s why we encourage people to enter into randomized controlled trials so that we can actually look at this in an evidence-based way.
We are learning things. But it’s still early days. It’s about a year into this, and most of the attention has been on ways to keep people alive. But now I’m hoping that things will settle a bit and the attention will be on people with residual symptoms and trying to figure out what’s the best way to help them.
TVO.org: Was there any skepticism about long-haul COVID-19 from parts of the medical community, as we’ve seen with chronic Lyme disease, Chronic Fatigue Syndrome, and other similar conditions? Because research seems to be finding similarities between these conditions.
Cheung: I can tell you that there are similarities between it and what we call Chronic Fatigue Syndrome — the newer term is myalgic encephalitis. For some people, it may be triggered by a viral infection. And for some people it may be triggered by something else, like a concussion. It is a condition, sort of like Chronic Fatigue Syndrome, that is not very well understood. There is ongoing research around people with CFS and trying to learn more about what can help. So there are some similarities.
TVO.org: Can long-haul research move some of the science and treatment forward on these conditions?
Cheung: Yeah, I think so. One good thing about the pandemic is that it has moved science forward in a number of areas. And I’m certainly hoping that it will move science forward in this area as well.
TVO.org: Will establishing research and clinics be an important step in the public-health response to COVID-19?
Cheung: I do think we should expand it. How the United Kingdom works is that they have a national health system. They can say, “We’re opening 30 clinics.” Here, it’s like every province has to fight for it, because the dollars are at the provincial level. They’re not at the federal level. Currently, we have, like, 10 or more health systems rather than one that says, “Let’s put this in.” And it’s done.
TVO.org: Do you have anything to say to people dealing with these symptoms who may be anxious about their condition or unsure how or whether they’ll get better?
Cheung: One of the concerns of patients is: Are they going to be like this for the rest of their lives? And what I can say is, in my care of patients with long COVID symptoms, they do get better with treatments. We are still trying to work out what is really the optimal treatment. But I do see patients getting better. I would love to be able to tell people that by doing A you would have it way shorter than by doing B. And that’s really what’s missing. I would like to be able to answer those sorts of questions as to which therapy is the best and most optimal for you. I am not sure we are at a spot where we can say that, even though we’re using all sorts of things. But I see that people are getting better.
This interview has been condensed and edited for length and clarity.