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Standing Committee on Health, Aged Care and Sport
Impacts of long COVID and repeated COVID infections

THEVARAJAN, Dr Irani, Infectious Diseases Physician, Victorian Infectious Diseases Service, The Peter Doherty Institute for Infection and Immunity [by video link]


CHAIR: I would like to welcome Dr Thevarajan from the Peter Doherty Institute for Infection and Immunity. Thank you very much for coming today. I welcome you to give evidence to the Standing Committee on Health, Aged Care and Sport. I will remind you that this hearing is a legal proceeding of the parliament, and the giving of false or misleading evidence is a serious matter that may be regarded as a contempt of the parliament. The evidence given today will be recorded by Hansard and attracts parliamentary privilege. I now invite you to make a short opening statement.

Dr Thevarajan : Thank you for the invitation. I'm one of the infectious diseases physicians and I've been involved in both clinical care and research of COVID-19 infections, in both a hospitalised setting and a follow-up context. I've mostly managed patients that have been acutely unwell and hospitalised with COVID-19 infection. Through the multiple surges across the last 2½ years I've witnessed the morbidity and mortality affecting these patients, particularly in what we consider vulnerable cohorts in more recent surges, and I've also witnessed reinfection and the development of long COVID along this process.

I mostly want to talk about long COVID and existing understandings and research in my experience and capacity as a researcher at the Doherty. As you've probably heard during this process, long COVID is quite a complex syndrome, with protean manifestations and multiple organs involved, and we're learning all the time from both international data and some local cohorts about the breadth of the multisystem effect of long COVID. It's also important to mention the psychological impacts of long COVID.

We perhaps don't have a lot of information or understanding of the incidence of long COVID on a population level in the Australian context. We have some data to suggest that we are seeing different incidence and prevalence compared to international cohorts, but we haven't had large population-level studies to understand this better in our context. The reason I'm emphasising that our context is perhaps different from international contexts is that we've experienced a larger burden of infection in a vaccinated population, which does make us a distinct population compared to other cohorts and other studies. I think it's important, therefore, to understand our context, and I think it's critical for us to have large prospective cohorts to understand the health impact of this as well as reinfection.

Similarly, in terms of prevalence of long COVID, I also think that we have some way to go in having studies in our context to understand what the actual prevalence is. There is some modelling data that gives us some information, but actual prospective cohorts to understand this is really important. There's a good increasing body of evidence to make us understand the risk factors for developing long COVID, and a lot of that does come from international data. We understand that there's a gender predilection for long COVID, that being female. We know that there are multiple comorbidities that are associated with developing long COVID. A high viral load diagnosis might relate to the pathogenesis of why people develop long COVID. We also know that those of poor socioeconomic status or of an ethnic minority seem to have a higher proportion or higher risk of developing long COVID. Again, as I mentioned earlier on, I think that we need to have a greater understanding of this in our context as well.

Lastly, I want to mention that there's also a need for clinical trials in our context in large populations so that we actually understand and accelerate our treatments for long COVID. I'll stop there.

CHAIR: Thank you very much. The member for Higgins will start the questions.

Dr ANANDA-RAJAH: Thanks, Irani. I should just disclose that Irani and I trained together a long time ago. With respect to treatments, what kind of treatment are you proposing? As far as I understand, there are not many treatments for this condition. Are you thinking of a bundled care approach or something else?

Dr Thevarajan : At the moment, there's a multimodal approach to treatment. Because of the complexity and the diversity of the clinical presentation, there's a need to understand what kind of treatment, what kind of approach and what kind of model of treatment is actually ideal for those that experience long COVID. I absolutely agree there's no specific treatment or drug, but having a model and an approach, whether it's a bundled approach or it's a bundled then targeted approach, is an important area that we need to understand.

Most patients, in the current context, will get referred to their GP. Their GP will most likely start a set of treatment approaches, but also, if those treatment approaches are not successful—it depends on what they've actually presented with—will refer them to a specialist or to a long-COVID clinic. As you may have heard earlier, we have long waiting lists in our long-COVID clinic. Patients often have ongoing symptoms without having an approach or an opportunity to have those symptoms addressed. It's important to get a greater understanding of how to efficiently and effectively approach patients who are suffering from long COVID, as well as what the best model of care is.

Dr ANANDA-RAJAH: You mentioned earlier that you thought that there was perhaps an over-representation of socially disadvantaged and ethnic minority groups. Could you elaborate on that?

Dr Thevarajan : It's come through in some of the studies that have occurred, and it's been represented in multiple studies. That might be related to the access to care that those in poor socioeconomic circumstances experience. We may be seeing that they don't get early access to care, whether that's early access to care in the acute-COVID setting or whether it's access to care in the post-acute-COVID setting. I don't think that we have the answers. I think it's speculation at this stage, but we've certainly seen in repeated studies that those of poor socioeconomic circumstances seem to have a higher risk factor of developing long COVID.

Mrs McINTOSH: Thank you very much for your presentation. It was really thorough. My first question relates to a comment from a previous witness who said they're giving patients reassurance that they will not be permanently damaged by long COVID. Can you give those same reassurances, or is it dependent on the severity of the initial infection? Do you have that same level of confidence?

Dr Thevarajan : The short answer is no, because I don't think that we know yet. We do know that a large majority of patients that develop symptoms post acute COVID have resolution of a large majority of their symptoms by the time they hit the 12-week mark. We have seen that. However, there's a significant proportion of symptoms that persist beyond 12 weeks, and that's not just from clinical or anecdotal experience. We also know that the literature supports that t here is a proportion of patients who continue to experience symptoms. In New South Wales cohorts, the proportion of patients that have continued to experience symptoms post three months is about five per cent. However, there are UK cohorts that report a higher proportion of about 14 per cent. We've had other cohorts that report up to 30 per cent. I don't know that we can really say that with confidence yet, because we haven't had the benefit of time from when this all started to know that people will end up completely cured.

We also don't fully understand the pathogenesis. There have been biomarkers, there have been immune pathways, there have been persistent COVID antigens. There has been a real burst in the literature to associate why some patients end up with symptoms beyond the three months, but we don't know what that means, what the impact of that is and how long those markers will last. I'm not sure that we can yet give people the assurance. We've had some studies that indicate that people can end up with neurological complications two years post COVID, and we're 2½ years post when all this started. I think it's early days to be able to give that answer.

Mrs McINTOSH: Thank you. My next question is around people presenting that have existing mental health conditions and the impact of mental health conditions on other symptoms of long COVID.

Dr Thevarajan : I mentioned that there were some pre-existing comorbidities that have been identified as risk factors for the development of long COVID. There are ones like diabetes, obesity, smoking and asthma. There are also pre-existing psychological conditions. If you've got a pre-existing psychological condition then you have a higher risk of developing long COVID. Then, to add to that, there have also been studies—speaking separately as well—that have clearly shown that, whilst mood and anxiety disorders post COVID might be transient, regardless of whether you had a pre-existing psychological condition or not, there are psychiatric conditions, including psychotic disorders, that persist for a prolonged period of time post COVID. There is a link. Again, I do feel that it needs a greater understanding, and we probably need to get a better understanding in our context as well. This is really coming from studies that occurred internationally.

Mrs McINTOSH: That's really interesting. You're saying that's also in people who never presented with psychological issues previously?

Dr Thevarajan : Yes. It's identified as a risk factor but, putting that aside, there's a clear psychological impact from having long COVID. Some of it is transient; some of it is persistent.

Mrs McINTOSH: Are you seeing other medical conditions develop amongst patients who have had long COVID?

Dr Thevarajan : Yes. This sort of comes back to that really complex collection of symptoms. I think what's occurring is that there's a lot of follow-up. There are some Victorian cohorts and a really large New South Wales cohort that are specifically looking at cardiovascular, respiratory, gastrointestinal and neurological. They're looking into this information. I don't know that I can definitively say that there's an absolute new condition or whether it's an exacerbation of a condition that was pre-existing or was going to happen. I don't know that we have that information yet.

Mrs McINTOSH: Thank you very much.

Ms STANLEY: Thank you very much for your information this morning; it's been very interesting. We've heard a number of times and you've reiterated that there's not good data around the Australian experience. In your experience, what do we need to do to get that data started and happening [inaudible]? Any insight you've got would be wonderful.

Dr Thevarajan : I think there are some really good clinical cohorts occurring. There are definitely more deep-dive cohorts that are looking at immunological mechanisms, biomarkers and so forth. What I'm really talking about in terms of incidence and prevalence is large population based studies. I think we need to collect information across the nation, across our population, on a large level because that's where we're really going to pick up patterns and trends in a more reliable way. It's a numbers game, as often is the case with research. The larger the number that you study the more confident you can feel about the data that you observe.

Ms STANLEY: Is it a lack of funding to do that research currently or, even if we funded that research, the actual datasets are not available and we need to, today, start saying that people who present from today need to tell us X, Y, Z, W so that six months into the future we can actually start this data? Does the dataset actually exist in a reasonable form that you could be confident with what you find, or do we need to say 'this is the data we need to be collecting' and therefore do it today?

Dr Thevarajan : I think it's about creating the networks. I'm probably not the best person to comment on funding. I know there's been quite a bit of funding that has been distributed for this kind of purpose, but that's not my area. I'm walking out of my area there. I will say that it's about creating networks and optimising the networks so the data can be collected in a consistent, large-scale way.

Ms STANLEY: You don't have access to that data collection at the minute?

Dr Thevarajan : No.

Ms STANLEY: You made a comment, and others have commented as well, about the incidence of COVID particularly in poor socioeconomic situations and people who come from that sort of a background. I've read, and it is my experience, that people in poor socioeconomic backgrounds tend to be the ones who got COVID because of the type of jobs they did and because of the circumstances of overcrowding. Is that one of the reasons why they are more representative in long COVID? Are we sure there isn't something else going on and [inaudible] proper representation [inaudible]?

Dr Thevarajan : I think it's a difficult question to answer. You are absolutely right that their living circumstances or work conditions might have predisposed them to be at a higher risk of acquiring the infection, particularly when we were going through our peaks. I think that's a really important point. This is purely speculation, but there are studies that have come out that have shown that being vaccinated is protective against developing long COVID. Again, this is speculation. I'm not sure about the access to and acceptance of vaccination in these groups. I think that's worth looking at. It's really hard to know that information. I think that's one aspect.

There is also the access to care, whether it's access to care during the acute COVID infection or access to getting all the appropriate help when you start to develop post COVID symptoms. Getting access to a cardiologist, getting access to respiratory physicians, getting access to a psychiatrist and a neurologist—I can't imagine that they would be easy areas for someone who has socioeconomic limitations. I do think that's an incredibly hard question to answer. It could be multiple factors. It's certainly something that I feel we should look at because it has come up as a risk factor in several studies.

Ms STANLEY: I thank you for your candour. It has been a really interesting conversation. Thank you very much.

Dr RYAN: Thanks very much for your input. If we gave you all the things that you wanted to run your service, what sort of things do you think would be helpful to improve the quality of the service that you're providing and the data that you're collecting?

Dr Thevarajan : I think, importantly, having the resources to start to both explore and implement a network for data collection, because we need to understand the data to then know what we need to actually do and how we approach or formulate a solution. So I think, in the first instance, it's actually really getting a better understanding of long COVID. I would say that that's where the focus is for us, so that we get a better understanding of what is the actual incidence and prevalence and what are the risk factors in our context, because we did have a population that was vaccinated in the context of when we had our peaks. What are the limitations? What's contributing to the risk factors?

Moving from there, we need the networks to understand what the clinical impact is, in both the short and the long-term. Then, in terms of treatment, I think that's a real area that needs—a lot of patients that suffer from long COVID have to go through a couple of steps. The first is recognition that they've got long COVID, the diagnosis. Then they've got to actually access the right kind of care. Then they've got to be put into a program that helps them. So there's a whole pathway there where we could think about the model of care. I'm not sure if I've answered your question well, but I think, in the first instance, actually implementing networks to understand exactly what's going on in our context is important. We're going to face reinfection. We're going to face that moving forward, and I think we want to know what the impact of reinfection is in our population.

Dr RYAN: I just wonder about this, because we know that, with reinfection, your chances of developing long COVID increase quite significantly. It would be very interesting to be able to follow people from the time that they're diagnosed with COVID again to see what differentiates those people who develop it from those people who don't. But, as far as I'm aware, no-one's really doing that anywhere. Would that be fair to say?

Dr Thevarajan : There are a couple of really good prospective cohorts. I think you will hear about it later on, because I believe the Kirby Institute is presenting, so you'll hear about the New South Wales cohort. I'll let them speak to you, but they are certainly following a cohort across a longitudinal period—so reinfection and impact and change in clinical studies. I would imagine that would shed a really good light on the clinical syndromes. But that's not going to represent the large group of patients. So I guess what I'm trying to say is: the larger that dataset and that follow-up are, the greater representation we have of the different populations within our context, and we get a better understanding of who gets impacted and what that actually means for us.

Dr RYAN: I suppose the only other thing is that some people have, I know, pointed out some similarities in what people think might be the pathogenesis of long COVID, as opposed to people who've had issues with vaccination, and some of the specific vaccines with the spike protein and stuff like that. Are you collecting that sort of data, in terms of relationship to infection with COVID, the timing and type of vaccination that people are receiving and then subsequent development of specific long COVID symptoms?

Dr Thevarajan : We have a very small cohort that we are following at the Doherty, but I don't feel that that's going to give the large-level answer. So I'm not aware of any large cohorts or large studies that are collecting that information.

Dr RYAN: Thank you.

CHAIR: Thanks, Monique. Thanks very much, Dr Thevarajan, I've just got a couple of questions. Ms McIntosh, Ms Stanley and I work in areas of Sydney that have been most severely impacted by COVID. I'm very worried that, from the evidence we've heard so far, there is significant recruitment bias from some of the places we've heard from, in terms of the cohort they're following, and that those that are most at risk and most disadvantaged are not actually being followed or having their data collected. Would you like to make any comments on that, and is the Doherty trying to have a more balanced data collection cohort?

Dr Thevarajan : It's a good point. I think—and I've alluded to this before—that it is important to get as large a data collection set as you can so that the population-at-large is represented well. I agree that that is a potential concern of bias, as in the data. In terms of what the Doherty would like, Doherty has funding for APPRISE, which is a large national network. One of the intentions with APPRISE is to try and collect large-level data. It's in its infant stages in terms of what that's going to look like, some of the discussions around that and what the proposal is. I can't really inform you of anything further in terms of what that particular network is doing, but it certainly is on the wish list of what we'd like to do.

CHAIR: So, if we're going to look at data, we have to look at large datasets nationally. Is that what you're saying?

Dr Thevarajan : Correct. Large datasets nationally will give us a good, broad, large database to work with, so that we can get the kinds of answers that I think we'd really like to. It would likely minimise bias because of its breadth and its size.

CHAIR: Great. Are you doing any work with the general practice networks to look at this?

Dr Thevarajan : I can't answer that. I know that some respiratory physicians, certainly in Melbourne Health, have linked up with multiple other physicians who are involved with long-COVID follow-up, and they are involved with GP networks, but I can't really inform you on exactly what that involves or what that looks like.

CHAIR: Okay. Thanks. The other thing, and probably the most important question, is this: we've been hearing lots of anecdotal [inaudible] role. Can you see these numbers for long COVID overwhelming the health system?

Dr Thevarajan : There are increasing waiting lists, certainly for our clinics. I'm talking about the Melbourne Health context. We know that we've got an increased demand for review for long COVID. There's a lot of active discussion about how we can expand our resources to provide the appropriate kind of care for these referrals and for this group of patients. So, yes, there's an active care. I wouldn't say it's overwhelming the health system. I just think that we've got increased demand and we're trying to meet that demand by increasing our resourcing capacity, which we feel confident that we'll be able to do.

CHAIR: So you do feel confident that you'll be able to deal with the numbers?

Dr Thevarajan : We are in active discussions about how to increase our capacity, so at this point in time, we feel confident that we'll be able to meet the numbers.

CHAIR: Are you looking at any innovative solutions for that, like digital platforms et cetera?

Dr Thevarajan : I would have to get back to you about that. I'm not really sure what the discussions on the ground are with the actual teams involved. I'm not a hundred per cent sure about what's being discussed.

CHAIR: What's your clinical impression about the best ways to support these people?

Dr Thevarajan : My clinical impression is that they require a multidisciplinary team approach. That's been my clinical impression. They might have one prominent area or symptom, but there are often multiple things. For example, those who suffer from palpitations or cardiological kinds of symptoms also have a psychological impact from suffering from these symptoms four months down the track from their acute COVID infection. Having a multidisciplinary, very well-connected approach, where, if they then report other symptoms, we can link patients in with the other specialists is very important. There's an overlay of also having allied health. A lot of these patients require physio input and social input. It's really about getting a whole team with all the disciplines involved and having that at hand to support these patients. That's really what I was alluding to before when I was saying that we're looking at how we can up our resources and up our capacity to support patients in the Melbourne Health context.

CHAIR: One last question I have is that there some people who are likening long COVID to previous iterations of chronic fatigue syndrome, myalgic encephalitis et cetera. Is your impression that this is the same illness, or is it different? Should we be looking at similar supports?

Dr Thevarajan : There are certainly some common themes there. I don't know that we ever really understood chronic fatigue syndrome very well. It's a complex syndrome. That's definitely a parallel with long COVID. Long COVID is, in a similar way, complex. Whilst we're gaining understanding, I think we've got a long way to go. I don't know that we can necessarily put it or not put it in the same category. I think we are seeing some similarities. The pathogenesis of COVID is still being unpacked, so it's really hard to say it's similar to what happened in long COVID. I do know there's a lot of discussion about the fact that, in a similar way that chronic fatigue can affect multiple organs and present in a myriad of symptoms—that's what we're seeing in long COVID. But I'm not sure that we have the data to sort of extrapolate any more that than that.

CHAIR: Are you aware of any treatments, apart from the multidisciplinary approach, that work for long COVID?

Dr Thevarajan : No, I'm not. I'm not aware of any specific other treatments.

CHAIR: Thank you very much. Once again, thank you so much for giving us your very valuable time today. We really appreciate it. It has been really frank and really interesting for us. If you have been asked to provide any additional information, can you please forward it to the secretariat by Friday 28 October. You will be sent a transcript of your evidence and will have an opportunity to request corrections to any transcription errors. Lastly, do you have any questions for us?

Dr Thevarajan : No, I don't. Thank you very much for your time.

CHAIR: And you will be making a written submission to the inquiry?

Dr Thevarajan : Correct. Yes, we will. Thank you very much.

Proceedings suspended from 10:56 to 11:32