9 minute read
of the GP
HealthYourUnderstanding C VID
Voice of the GP
Editor Michael Walls sat down with Western Sydney GP, Dr Kean-Seng Lim to explore some common myths and thinking around living with COVID.
Michael Walls: I wanted to get a bit of a sense around immunity and COVID. I mean, what we can do to make our bodies more resilient to catching COVID or recovering. Dr Kean-Seng Lim: So that’s an interesting question that one. The bottom line is that COVID is a virus like many other viruses. So, what we would do to try to keep ourselves as healthy and as well as possible is the same as we would for any virus. This starts with our own personal health, which means healthy diet, healthy exercise, healthy weight, try not to smoke, try not to drink too much, and stay as well as possible from a general health perspective. There are no vitamins or particular supplements that you can take, which are going to help you reduce your risk of getting COVID, nor in fact, any other virus for that matter. It’s just general health. So, our best ways to prevent getting COVID are still the same ways that we’ve been talking about all along, which is wearing masks, which would be highly recommended in any social setting, whether we’re going shopping, to school or visiting people, so wearing masks is still number one. Number two is social distancing. So, this means that when we are in the shops, we should still be watching out for that 1.5 metre distance as much as possible.
Michael Walls: And what specifically of social gatherings?
Dr Kean-Seng Lim: If we are having social gatherings, we can do them in an environment which has got good air flow and good air turnover, that will also reduce our risks of catching COVID. So, it’s a combination of keeping ourselves healthy, but also trying to be aware of how covid and other illnesses are spread and trying to do our best to avoid catching it, or rather trying to avoid transmitting it and catching it from these airborne masses.
Michael Walls: I heard Dr. Nick Coates on the radio saying that if you’re really being serious about dealing with COVID, you could lose weight, get out go for a walk. Do you subscribe to this thinking? Dr Kean-Seng Lim: Well, that’s it. Okay. Now this one’s an interesting one, because there’s two elements to this question. The first one is risk of catching, and the second one is of having severe disease. I am not aware that weight increases or decreases your rate of catching COVID, because catching COVID is almost the luck of it, in that, if it’s floating in the air, you’ve got to try to make sure you don’t get it into your lungs. Which is why the masks and social distancing, as well as the high airflow environments are important, and of course vaccination. What we do know is that certain things predispose you to getting more severe COVID, and obesity is definitely one of them, along with poorly controlled diabetes, poorly controlled kidney disease. In fact, any chronic illness is liable to make you more likely to get severe COVID. So, it’s a slightly different question, or rather answer to catching COVID. It’s about how do I stop from getting severely unwell from COVID. And for that one, it is weight. It’s also about making sure that whatever conditions you have are well managed (so that’s asthma, diabetes, heart disease, lung disease), and of course, being vaccinated.
Michael Walls: To what extent does being fit play in resilience to COVID? There’s no real rule of thumb, is there?
Dr Kean-Seng Lim: There isn’t and unfortunately, that’s one of the problems of COVID, which is that there is a certain randomness as to the severity at which you get it. So, while we can say that if you have poorly controlled chronic illnesses and you are overweight or obese, you are more likely to get severe COVID, we can’t say that everyone who is in those categories is going to get severe COVID. The same applies for fitness, the fitter you are, the more likely you are probably not going to come down with severe COVID or not be severely affected, but just as equally because there is a certain randomness, you could be the unlucky one who does get severely unwell.. The best thing still is prevention, which is why I’m going to come back to vaccination, masks, social distancing, and airflow.
Michael Walls: So, in terms of it’s in the air, can it linger? For example, if someone came into our house with COVID, can the virus still linger after the person has left? Dr Kean-Seng Lim: Yes. So, this has been another thing about COVID, because the virus has evolved and mutated from the very first version that we saw at the beginning of last year. Hang on, it was the year before now. Beginning of year before last. So, since the very first version, the virus has mutated. The first version did not seem to affect kids, so what we call the Alpha strain did not affect kids as much and did not seem to be as easily airborne. The evolution of the virus means that it’s now affecting kids more, it’s more contagious and it does seem to linger in the air more. The other element is, how much of the virus is in the air. How far can it go through the air and how much is in the air is dependent on a couple of factors. One of them is how much a person aerosolises. So, this means that if someone is singing loudly or is talking loudly, then they are going to project the viral particles more through the air. And the more the particles are in the air, the more it’s likely to linger. So, if you should walk into a room where someone before you has COVID and they were not wearing a mask, there is a high probability that there will be a lot of COVID virus floating around in the air.
Michael Walls: There seems to be studies done on this all the time, but are the masks very effective? So, in a group, say 250 businesspeople, ten people at a table. Now I know there’s no iron clad rule - but is it very effective, moderately effective? Dr Kean-Seng Lim: Well at a population level which means that everyone is doing it, the answer is it is actually very effective. And the reason is that masks protect not just against breathing it in, they also protect against projecting the aerosols through the air. So, if everyone’s using masks, that’s when it works best. The situation you described where you might be at a table of ten people and no one was wearing masks, the degree of infection risk in that situation will also depend on how loudly everyone was talking. So, this means, for example, if it’s a very noisy room, everyone’s going to be talking more loudly and they will project and spray aerosols around much more than if it was a conversation with the person next to you. There are quite a number of variables when it comes to this, but the bottom line is, masks are actually a very cheap, simple and effective way that we can continue to protect ourselves and others.
Michael Walls: So, if you’re the only one in the room with a mask on and no one else is, are you protected more so than the people who don’t have masks on? Dr Kean-Seng Lim: Well, you are. However, it does then in that case depend on what sort of mask you wear. Because in that situation, if you’re wearing a well fitted N95 or P2 mask, you are going to be better protected than if you’re wearing a cloth mask, because we know that cloth masks do not give the same level of filtration protection as a good well fitted mask does. So again, masks, and I think this might have been your question, there are degrees of protection from masks where a cloth mask is better than no mask, but it’s not going to give you as good protection as a surgical mask, which in turn is not going to give you as good protection as an N95 or P2 mask which is well fitted.
Michael Walls: What about hand sanitiser? I’ve heard mixed stories around that.
Dr Kean-Seng Lim: It’s important to consider that COVID is not the only virus out there and so we are going to be seeing more influenza, now that we have opened up the country and there’s more free travel and many other viruses and bacteria will be found on surfaces and can be spread from surface to person. Hand sanitisers remain a good way of protecting against other viruses, so we shouldn’t forget that. Also, while at this point, surface level spread is not looking like a major factor with COVID, it is possible that we will come across a time where we get a form of COVID which does persist and linger on surfaces as well given that COVID does mutate. Michael Walls: So how about spraying surfaces with Glen20 or other surface disinfectants, is that effective?
Dr Kean-Seng Lim: Sure, I’m not aware of any research done as to whether that is any more effective than wiping down with soap and water or alcohol. I think that in general we would say that wiping down the surface with a disinfectant is going to be more effective than a spray, in general, because you are going to be removing particulates better. But I am not aware of any studies which show that one way or another is more or less effective for COVID. Michael Walls: How about isolation? We’ve all heard of stories where one person in the house has got COVID and they’ve isolated and no one in the house has got it. Dr Kean-Seng Lim: Yes, absolutely. So, while there is a certain randomness to COVID in terms of how well it transmits to a household, that randomness is determined by a combination of vaccination, immune status and probably sometimes just the luck of things. We do know that if someone is isolating well, the risk of passing this condition, broadcasting this virus onto others is definitely reduced.
Dr Kean-Seng Lim received his medical degree from the University of Sydney in 1991 before undertaking his residency in the Hunter Region of New South Wales. He has worked at the Mt Druitt Medical Centre for the past 20 years, where he is able to offer the holistic, collaborative care that has appealed to him since his days as an intern. He is the recipient of the RACGP’s 2015 GP of the Year Award.
