Should we be worried about strep A?

This year, cases of an invasive bacterial infection are rising earlier than usual in the United States, the United Kingdom, and other countries across Europe. 

Infection with group A Streptococcus bacteria — commonly known as strep A — usually only causes mild illness. However, things have become severe in some cases, with several children dying in recent weeks.

So, should we be worried? And what symptoms should we look out for to help us identify this illness in ourselves and our families?

In today’s episode, Jonathan is joined by a world-leading expert on the subject. Shiranee Sriskandan is a professor of infectious diseases at Imperial College London, and her research focuses specifically on strep A bacteria.

Regular guest and ZOE co-founder Tim Spector also joins, and as one of the world’s top 100 most cited scientists, Tim has been closely following infectious diseases in the community through the ZOE Health Study

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Episode transcripts are available here.

Read about the ZOE Health Study.

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This podcast was produced by Fascinate Productions.


[00:00:00] Jonathan Wolf. Welcome to ZOE Science & Nutrition, where world-leading scientists explain how their research can improve your health.

In recent weeks, a number of children have died due to an invasive bacterial infection of group A streptococcus, more commonly known as strep. A. While most bacteria are our friends, this one is definitely not. It is common around the world and cases of strep A infections usually rise in late winter and early spring. This year, figure showcases are rising much earlier than usual in the US, the UK, and other countries across Europe.

Strep A usually causes mild illness. However, in rare cases things can become much more serious and this is happening more frequently than usual. Current data shows a more than threefold increase in cases of this invasive form In young children. Understandably, parents are worried. Unfortunately, much of the information available online is murky and the usual misinformation is already circling on social media. So in today's episode, I'm joined by world-leading expert on the subject, Professor Shiranee Sriskandan, whose scientific research focused specifically on strep A bacteria.

I am also joined by Tim Specter, one of the world's top 100 most-cited scientists. My co-founder here at ZOE, who's been closely following infectious diseases in the community through our ZOE Health Study.

[00:01:39] Jonathan Wolf: Shiranee, thank you for joining me today. We'd like to start with a quick-fire round of questions from our listeners, and we had a lot of questions from our listeners around this topic. I would say one of the largest set of questions that I've seen, and we have a very simple rule, we always do for this, which is always really difficult for scientists, which is you can say yes or no, or a one-sentence answer if you absolutely have to.

Are you ready to go?

[00:02:06] Shiranee Sriskandan: Possibly

[00:02:07] Jonathan Wolf: You’re looking a little anxious. It's not that bad, I promise. I took my little girl to the dentist yesterday and she was really anxious, so it won't be as bad as that. Alright, so is there a lot of strep A infection at the moment?

[00:02:23] Shiranee Sriskandan: There is, yes.

[00:02:26] Jonathan Wolf: Can some children get really sick with strep?

[00:02:30] Shiranee Sriskandan: Yes, rarely.

[00:02:32] Jonathan Wolf: And should parents be panicking?

[00:02:35] Shiranee Sriskandan: Definitely not.

[00:02:36] Jonathan Wolf: Brilliant. See, that wasn't that hard. Tim, is there an increased level of all infectious diseases like cold and flu and covid this winter?

[00:02:46] Tim Spector: At the moment, absolutely, yes. We're seeing lots of infections.

[00:02:52] Jonathan Wolf: Next question. We had this a lot. If my child has to take antibiotics for a strep A infection, will it destroy their gut microbiome?

[00:03:01] Tim Spector: Probably not.

[00:03:03] Jonathan Wolf: Alright, well look, I think we're gonna get into all of that now through the rest of the podcast. And I think, Shiranee, what I'd really like to start with is, what is this strep thing that suddenly we are hearing about all the time?

[00:03:17] Shiranee Sriskandan: So this strep thing is a bacterium called Group A Strep. Strep Pyogenes, Strep A, whatever you wanna call it. And it's been around for a long time in our history, a long, long time. It normally causes infections of our throat. It can cause infections of our skin, but unlike some bacteria that you may have heard of, it's not something that normally lives in our throats and our skin.

It's an abnormal bacterium, so it's not a friendly one at all. And very rarely it can go to parts of the body where it shouldn't be and make us far more sick than we should be. But in general, it causes these self-limiting infections of the throat or of the skin. And those get better quite often on their own, but more quickly with antibiotics.

[00:04:04] Jonathan Wolf: And how common is it normally and how common, I guess, is it right at the moment around the world, this winter.

[00:04:14] Shiranee Sriskandan: So it's very common. But, we see it in different seasons in countries like the UK and the US for example, the Northern Hemisphere. So we tend to get sore throats from group A strep. Actually, interestingly, not in the peak winter season when we get the viruses that cause flu or RSV, but usually actually in the early spring.

And we don't really understand why that happens. But anyway, we get sore throats then. And I would say that every single child has had a strep sore throat by the age of five or six. So it is very common and a lot of children, as we know, get sore throats quite frequently throughout the year.

Many, many of those will be viruses, but we do know that, most of them will have had Group A Strep by the time they're five or six. So it's not something that is alien to us as humans. What's really interesting is in hotter, more tropical countries, Group A Strep seems to cause more skin infections than throat infections.

So you get more infections like impetigo or something called pyoderma, which is a sticky sort of scabby skin infection. Both of these things are very infectious to other children though, so it's common when it causes these skin or throat infections, but it's not normal for the bug to live in the throat.

[00:05:29] Tim Spector: What's odd this year is that it is coming at the same time as we're being hit by other viruses that particularly are also having sore throat as their top symptom. And this, I guess is what Shiranee is saying is particularly unusual, although every year varies. So, you know, there's this cyclical, just like the viruses for reasons we don't really understand bacterial infections also vary year to year, quite a lot. So at the moment we've got this triple whammy of virus symptoms in children and adults that are causing sore throat as the number one common symptom, which also happens to be the sort of trademark symptom of strep throat. So that's why we're sort of in a particular pickle at the moment that generally it would be out of season, and you wouldn't have these competing other infections which are all at the moment still going upwards.

[00:06:30] Shiranee Sriskandan: Which makes it very difficult isn't it for the poor old parents and the doctors and clinicians trying to see the children working out what on Earth's going on? But it's also a double whammy because clearly one thing can make the other thing worse, and we know that from history. So we always know that, somebody who has pneumonia and has had something like flu or RSV beforehand will maybe do worse because of having both together.

But what I would say is that Group A Strap has been climbing throughout the year in an abnormal fashion. So I don't think we can blame viruses for everything, but the fact that now we've got Group A Strep occurring in the wintertime when it shouldn't normally be doing that, is clearly putting us in a bit of a problem.

[00:07:11] Jonathan Wolf: And so you're saying that actually it's not started in the last month or two as we got into the winter in the northern hemisphere. But actually you've already been seeing cases throughout the year. And is that very much like a strange post-lockdown, post covid sort of phenomenon or do you see that in other years in the past also?

[00:07:30] Shiranee Sriskandan: So I guess we're quite lucky in England in that we bean count a lot in terms of infections like this. So Scarlet Fever, which is kind of a very historic thing we've heard about it in Little Women and so on. So it was a really big deal over turn the last century. But we've been counting cases of Scarlet Fever since that time, since the nineteen hundreds.

And we know, Scarlet Fever, which is just a kind of old phenomenon that can occur with a strep throat. Sometimes in some children, we know that's a marker for how much strep throat is around and really, it was very, very uncommon after I guess the eighties and nineties.

So we really didn't see very much of it. And then suddenly around about 2014 in the springtime, we suddenly saw a lot more scarlet fever. And we've been seeing that sort of going on annually, really. And then of course when lockdown happened in March 2020, those rates of scarlet fever and therefore strep throat kind of went away for a long period of time.

And, so it's not entirely new, but I guess at the beginning of 2020, it looked like we were in for another bad year, and then we didn't have that because we all kind of stayed indoors and stayed away from one another.

[00:08:47] Jonathan Wolf: And so I think what you're saying is there's, interestingly, it's not just a sort of post lockdown, occurrence. You are saying you've seen this since about 2014, so almost a decade. So there's maybe more than just this sort of reassertion of…

[00:09:02] Shiranee Sriskandan: Yeah, exactly. So, we particularly in the British Isles or England has a particular apparent problem with Group A, which has been going on for the last sort of eight years, but it's obviously concatenated with all these other things to,  leave us where we are today, which is we've got a big rise now in the wintertime, which is not when we'd normally have it coinciding with winter viruses and also coinciding with kind of cohorts of children who will not have seen Group A Strep for the last two years.

And we know that because we didn't see it either in the hospital.

[00:09:39] Jonathan Wolf: And can I ask a bit more I guess, why we care? Because you've just described something you said like it's a sore throat, and everybody gets it. So that doesn't sound like anything you need to worry about. But on the other hand, you know, we have a lot of listeners who are sort of panicking about potentially really serious outcomes.

Could you just talk us through that gap between something that sounds like we have no reason to worry and people really being worried about what might happen to their children.

[00:10:08] Shiranee Sriskandan: I mean, this is kind of one of the reasons why we generally don't worry about a sore throat is that actually most of the time, even if it's caused by Group A Strep, it often gets better on its own. And also testing for it is done differently in different countries. So for example, we tend, GPs tend not to test for strep throat in this country, but in the US they use rapid throat tests and so on.

Why should we worry about it? I guess my view is that the reservoir if you like of this bug is in the community, it's the Children with strep sore throats and very, very rarely this bacterium can get into parts of the body that it should not get into. And I think it's really important to stress, this is not just in the children who've got the strep sore throat and, mostly it's not, they act as the reservoir for infections where the strep gets in, for example, through a break in the skin. I mean, that could be an accidental break, for example, an injury, or it could be somebody with chickenpox or somebody with a pressure sore or somebody with surgical wounds and someone who's just had a baby. 

And if you have a massive increase in the community of people out there with a strep throat, the risk or the number of people who are gonna then develop these much, much rarer invasive infections is gonna be much greater.

So it's a linear relationship, I guess, but we just don't know exactly the nature of that relationship. So it's not just skin breaks. Also, clearly the bug can get in past the throat, into the lower respiratory tract, into the lungs and cause pneumonia or fluid on the lung, empyema, which is something that we've been seeing in children. And that probably is more likely when you've got respiratory viruses, but it can happen even without respiratory viruses. So there is one other thing I'm gonna slip in, and that is that outside of countries which have access to good healthcare and prompt treatment, we know that if you have repeated strep infections in childhood, you can develop autoimmune problems afterwards. So even in children, they can get a disease called rheumatic fever, which can affect the heart valves and cause valvular heart disease.

[00:12:15] Jonathan Wolf: And just to clarify, Shiranee, the rheumatic fever is a consequence of the strep infection.

[00:12:19] Shiranee Sriskandan: Correct. It's an autoimmune consequence, so it's not the strep infection directly causing it. It's the immune response to it, and nobody really understands quite how that happens. But it's a disease that Britain knew all about back in the nineteen twenties, thirties and forties. And in fact, even after the war, we had cases of rheumatic fever and also something called glomerulonephritis, which is inflammation of the kidney, and basically a number of different autoimmune problems that can arise after a lot of Group A Strep infections. So these are incredibly rare in England and we just really don't see them very much. But in the developing world, they are far more frequently seen, and that's probably due to access to healthcare.

And the real, you know, worldwide one of the reasons why people want a vaccine against this bug is not to prevent the annoying sore throats that we've been talking about just now, and actually it's not even to prevent the deadly invasive diseases we've talked about. It's to prevent those autoimmune problems that can follow. Because worldwide, the biggest burden of this disease is actually in low and middle-income countries where they have lots of strep infections in kids, and then lots of these awful problems afterwards, which affect the heart and the joints and so on and the kidney.

[00:13:35] Tim Spector: And it's called Rheumatic Fever for that reason, Jonathan. So as a rheumatologist, we'll learn all about autoimmune diseases and causing this pain, and it's a very similar model to people who suffer from rheumatoid arthritis or juvenile arthritis. The body's immune system is reacting against, in a way itself and, I think that's the really interesting dark side of why we're so interested in this particular microbe.

[00:14:04] Jonathan Wolf: And so to make sure  I've got this cuz, I think part of the reason everyone's confused is it's quite complicated, isn't it? You know, it's not really simple. In a sense, you're not so worried about most people getting this strep. It sounds like every single one of us as an adult you're saying has sort of gone through this and probably had it multiple times.

It's the small number of people where you actually get this really serious infection where the bacteria is no longer on my throat, but actually it's either gone into my lungs or it's got elsewhere into my body. And at that point it has the potential to be deadly. Is that right? Is one angle?

And then the other part you're saying is even if it isn't deadly, it potentially triggers these autoimmune issues, which I live with for the rest of my life.

[00:14:46] Shiranee Sriskandan: Yeah, those things don't really tend to happen very often in northern temperate climates, and nobody really understands why that is, but it's probably due to sort of prompt treatment that happens in those countries.

[00:15:03] Jonathan Wolf: And Shiranee, just on the treatment, just to make sure we've got the basics before we dive in even deeper. So what is the treatment, and at what point I'd love also to understand what are the symptoms that you’re looking for if you are a parent. I've got a three-year-old, so this suddenly shot up my list of things to worry about. There's only so many you can worry about that means you should do something. And equally the point, there’s symptoms that say, actually you could probably stay calm and give it another 24 hours. Cuz if I took my little girl to the doctor every time she was sick, it would be three visits a week.

[00:15:37] Shiranee Sriskandan: Yeah. So, I guess for Strep Throat or Scarlet Fever, the symptoms have been read out a lot, haven't they? In the media the last couple of weeks. But it's a child who is unwell and poorly with a fever. Usually they will have, or they may complain of a sore throat or difficulty swallowing, but they may not, because they may not be able to articulate that if they're two years old, for example, rather than three or four.

But as a parent, you can actually peer into their throats. I wish people would do that a little bit more often. Obviously, try not to breathe in all of their droplets while you're doing that. But I do encourage parents to get to know the back of their throat because you can see a lot, and I mean, if you see big tonsils with white pus on them, that's not normal.

The other thing is that children often will get big glands up in the necks, which you can feel, and they will be tender. So that would be a good indication that they might have a strep throat, because obviously a viral sore throat will give you a very red throat, may well give you a fever. It doesn't usually give you giant tonsils with pus on and doesn't usually give you massive lymph glands in the neck. 

On the other hand, if they're very snotty and they've got lots of mucus coming out of their nose and they've been sneezing, that makes it slightly less likely to be a Group A strep. So those are sort of the indicators for a strep throat and in my view, does need antibiotic treatment.

Certainly at the moment we are encouraging doctors to treat strep sore throats. And the other thing is it is infectious to other people. So I would encourage people that if their child has been diagnosed with strep throat, even if nobody remembers to tell them that they should not really go to school for at least 24 hours after they've started their antibiotics.

So that's strep throat. and then scarlet fever is kind of, exactly the same as that except with the prickly rash, which can occur usually within a day. And it's a sandpaper rash. You can feel it and you can see it on the skin. It's like little bumps. So it's, it's a bit different to something like a measles rash or anything else cuz you can feel the rash and so it might not be red if you've got a darker-skinned child, but it's definitely there.

The children will get a very bright red, prickly looking tongue as well called a strawberry tongue. So again, scarlet fever, absolutely very infectious. Just like strep sore throat needs antibiotic treatment. And that is the one situation where antibiotic treatment for 10 days is recommended and definitely stay away from school for at least 24 hours until the child's had antibiotics.

But to be honest, most children, they're off school for two or three days cuz they feel rubbish. And that's normal. So thankfully nature does its bit to isolate the child.

[00:18:12] Jonathan Wolf: And just another clarification on the Scarlet Fever, because this is definitely, again, where it starts to get a little complicated, is the Scarlet Fever just a different set of symptoms to exactly the same infection, or is it actually something different from this normal Strep A infection you're describing?

[00:18:31] Shiranee Sriskandan: It is. It's different insofar as you get this rash, and that's what makes it scarlet fever. But remember, the rash usually follows a sore throat by day. So quite often you'll have a child who has this barn door strep throat who may or may not get diagnosed with a viral infection rather than a strep sore throat, and then quite often it's only when the rash appears that the doctor or the parent realize, oh, it might be scarlet fever, or it might be something else. So I think they are basically part of the spectrum of exactly the same infection. But who gets scarlet fever? Younger children and children who probably haven't met some of the toxins that this bug makes, that trigger this scarlet fever reaction.

So it's an immune reaction, a direct immune reaction to the toxins that this bug makes. It's a very old-fashioned disease. The rash in itself is, is harmless. Anf goes away. But other children will have met the bug before and they may have got immunity to the bacterium already. So they kill off the bacterium by their own immune system before the toxins ever get to cause the rash.

It's the same thing.

[00:19:33] Tim Spector: So just some comments based on the ZOE Health Study where we're still monitoring symptoms from our viruses and covid at the moment. Fever is actually pretty low on that list, and it's also very low in covid at the moment. We don't have accurate data. You may know more about very young children and covid, I suspect it's pretty rare in those groups as well.

So the distinguishing feature is not so much the sore throat, but it's this pus-filled, really nasty looking tonsils that you need to see and a fever, and really being very unwell.

[00:20:11] Shiranee Sriskandan: Yeah, so full disclaimer, I'm not a pediatrician, but I work on a pediatric infectious disease. So we've looked at children who've had, for example, Scarlet Fever and we've asked questions of their parents in a survey sometime ago, nothing as kind of spectacularly successful as ZOE app, but one of the things we found was that fever was a dominant feature of Scarlet Fever.

And the other thing is that obviously younger children will tend to present interesting symptoms that you wouldn't necessarily normally associate with a respiratory bug, so they may start vomiting, for example. I think that's just something that young children do when they have an infection, they vomit.

I can't really explain why. And it may just be that they get higher fevers than adults.

[00:20:53] Jonathan Wolf: I was gonna say, you're both gonna tell me you're not pediatricians, you're just world famous doctors. But my impression from a sample of a few children is also, they tend to run fevers more when they're very little than when they're older. Is that true or is that just my unscientific sample?

[00:21:12] Shiranee Sriskandan: I agree, but I can't say I've got any scientific backing. That's my impression as a parent.

[00:21:17] Jonathan Wolf: They're also worse at explaining what's going on. So I guess you're also, you're sort of as you said before, this is part of I think why one always worries a bit more when they're little, right? You are not sure that they can explain as clearly, and it's interesting what you're saying that at two, they may not be able to explain they've got a sore throat. By the time they're three, they probably can. My wife's a dermatologist and so, you know, she's always fascinated by the way the particular rash tries to tell you something and I laughed as you explained about the sandpaper rash because my wife is always pointed to something and being like, well, obviously it's this sort of rash.

And I'm like, It sort of all looks the same to me, so I'm always feeling that these are the sorts of things that doctors say to regular people to figure out, and it just creates more anxiety about whether you've successfully identified a sandpaper rash versus maybe their skin is normally like this.

[00:22:08] Tim Spector: But it's also, covid rashes occur very late. So they don't occur, you know, the day after infection and things like this. So there are quite a few other differences here that although any viruses can cause rashes generally, so, but they're not the same classical one as described here. But I think the key is the really nasty looking tonsils, very sick and the high fever that distinguishes it.

And people shouldn't think, oh, this must be covid because, there's lots of covid in the school. That's my view cuz Covid isn't producing that fever that it was at the beginning of the pandemic, and I think that's what most people aren't aware of. It doesn't even come in our top 20 list of symptoms in the  ZOE data now.

And I think that's really important.

[00:22:55] Jonathan Wolf: And I guess your message is in general, they're gonna be quite sick at the point you need to be worried. Is that also part of what we're taking away? Because I think that's often the question. So if you've got a two-year-old, you're gonna be anxious. And so the question is, you know, at the first sign of anything, are you straight off to the doctor or would you say still, they're gonna be quite sick, could still be lots of other things and that's what's triggering? How would somebody listening sort of help to figure their way?

[00:23:22] Shiranee Sriskandan: As long as we're still talking about the strep throat, scarlet fever end of the scale, children do get poorly. They're not kind of gravely ill, they're just, they are poorly. They're as poorly as they can be. Like Tim said, you know, you might have the tonsils or the red rash or something that points you to the fact that the child is not having a simple viral infection, but it might be a bacterial infection, it might be a strep infection.

What we're saying to parents at the moment is, at the moment there is a lot of strep about and far more than there might normally be, and therefore, what might have been a virus in a normal year might well be strapped and it might need antibiotics. And in those circumstances, you know, you can discuss it with your GP.

[00:24:02] Tim Spector: But in the, in many countries get a rapid test because, and there are places in the UK, according to my pediatric colleagues that do offer some, rapid tests and as well as most European countries you can get rapid tests done. So the UK is rather unusual in that it doesn't provide that for primary care services.

[00:24:25] Jonathan Wolf: And Tim, I actually really wanted to ask about this. I had a comment from one of our listeners that I loved, which said I've lived in the USA so I know all about strep throat. Why is it I've never heard of it in the UK until the last month. And I thought that was really interesting.

And in fact, I asked my mother about this because I also lived in the US when I was little, and she said I had antibiotics for strep throat about 10 times in my first five years while I was living in the US while my sister, who's much younger was born in the UK and she never had it once. And so it's sort of really fascinating to me because I had thought maybe it's just a disease that miraculously isn't in the UK, but I didn't really think it was very likely.

Shiranee is shaking her head, like, of course not. Could you help us to understand why this is a thing that like, you know, my many friends in America tell me about three times the winter that they have strep, their children have strep, and that if you're in the UK, like no one has ever mentioned it until today.

It seems really mysterious.

[00:25:29] Tim Spector: I think the problem lies not in the microbe itself, which is probably similar in both countries, but in the healthcare systems of both countries is my view.

[00:25:42] Shiranee Sriskandan: So I think there's a sort of cultural difference, isn't there, like you say, between the UK and other parts of the world, decisions about treatment are made on a sort of cost-benefit basis on the individual. So for example, the decision even to, you might not need to treat a strep throat is very different in this country compared with other parts of the world.

That's because we don't tend to see these complications of strep throats, the rheumatic conditions that Tim mentioned earlier. But if you go to someone like Australia and New Zealand, you will see posters up in surgeries saying, get your strep throat checked out and get treated. So on the one hand we've got posters up saying, don't come to your GP with a sore throat.

They've got posters saying the opposite.

[00:26:23] Jonathan Wolf: And look, you are one of the world experts on strep. So just, for your own personal view, like should we be testing for this? Put aside any cost question, but should we be testing and then treating or should we just not… Where would you go?

[00:26:39] Shiranee Sriskandan: If cost was not an issue, then I think it would be great to test and treat, but you'd need to really target the testing to people who've got a high probability of having a strep throat in the first place. So there are all these kind of clever algorithms that people can use. You know, is it likely to be a strep throat or not?

A bit like what we've discussed earlier, like are there big tonsils, are there glands up in the neck? And the thing is that these tests are either very sensitive. Which means they're based on their DNA test, a PCR test. We all know what those are now, but a lot of them are based on lateral flow type thing.

Again, we know what those are, and the lateral flow ones are 85% sensitive. That means that in 15% of cases, they miss the bug. So I think for a general population use, that's probably okay. You know, and, so for a doctor to be able to use a test and a sort of clinical decision making tool in their brain would be helpful. And then they could maybe prescribe potentially fewer antibiotics. We don't know.

[00:27:36] Jonathan Wolf: And I just wanna pick up on this. Actually antibiotics is something we had lots of questions on. And I think, you know, this being a show that's related to nutrition and we talk about gut health, and I think the antibiotics here is fascinating because we know they can save your life in lots of places, right?

So that's obviously really important. We also now know that they can have unexpected negative impact over time that we probably didn't understand a long time ago, but I'm interested that you said that you might actually prescribe fewer antibiotics, because I'm thinking about this US experience where in general I think we see this actually in our own data and our own members, where people in the states generally have had far more courses of antibiotics by the time they're 18 and then far more also in their adult life.

So it's interesting that you were suggesting that testing might actually reduce it. What are your thoughts?

[00:28:29] Shiranee Sriskandan: I think there are two things there. First of all, there's kind of healthcare use. I don't think we tend to go to our GPs very often. I mean, and that's for, for things like sore throats. Attendances to general practice have been declining for like two, three decades. I mean, I think we're quite, the British public's pretty well educated. They know not to kind of go to their GP, just like you said, with every kind of cough and sniffle. We don't do that, but actually in Europe, for example, they may well go and get something prescribed, even if it's not an antibiotic. We would not dream of doing that. So there's that. 

On the one thing, we're, we're not going to see our doctors to get prescriptions in the first place. But it is really just the idea that if you did a test that could distinguish this is a bacterial infection from, this isn't a bacterial infection.It's a strep throat or it's not. It would help the doctor in making that prescribing decision. Now we don't know whether that would increase or decrease antibiotic prescribing. I just would like to optimize it. I would prefer doctors just do the right thing.

I'm not interested in how much antibiotic is prescribed as being a metric, cuz I'd rather treat the patient.

[00:29:33] Jonathan Wolf: So I think that makes huge sense. And I think as a company that's very much around believing in understanding the data and also having more control over yourself, it seems pretty obvious that you would like to understand, what you have, if the costs are manageable.

[00:29:47] Shiranee Sriskandan: And I think the problem is that the tests that are used in many parts of the world are not, are not brilliant. But they are cheap and the test that we use in the UK is really good cuz it's culture. And also we can then get the bargain. We can test it for antibiotics, susceptibility and resistance, which you can't do if you do any of these other tests.

But it does take, you know, you have to get the swab to a lab for culture and it for a gp that means you won't get the result back for one or two days. So it's not very practical for them.

[00:30:15] Jonathan Wolf: I understand. Shiranee, I was also thinking you were saying that people in the UK are really well trained not to go to their doctors when they're sick, that there'll be all these other listeners around the rest of the world saying, that sounds completely mad so that they've all been trained basically not to see their doctors.

I don't want to get pulled down. That's a whole podcast in and of itself. Well, I think we are all being told that they're overloaded and you really shouldn't bother them unless it's really important.

[00:30:39] Tim Spector: So, yeah, things have definitely changed the last few years as people don't wanna wait and, and queue up for, you know, hours and hours to see an emergency doctor. They're more like to go to casualty than that. But, I'd slightly dispute the fact that the British are perfectly well-behaved and don't take many antibiotics because the data doesn't show that.

It shows that there is a gradient across Europe, where the Scandinavians take the least antibiotics, where they have the best healthcare, they have point of care testing and they take half the levels of antibiotics that we do in the UK. Although we are much better than many of the south Europeans. Places like Greece and Cyprus, et cetera, have really massive overuse of antibiotics as well where they can get them from pharmacies and much more easily available.

So I think most people agree that we could do a lot better than the Netherlands is much better than us, for example, in total amounts of antibiotic use. So we are overusing it, and this does cause major problems. The more people use antibiotics, the less effective they become, and you get more resistance to other bugs as well.

So I think there's obviously a fine line here and there's difference about talking in general about antibiotics and also very specifically about this particular problem of strep throat.

[00:32:03] Jonathan Wolf: And so Tim, could we talk maybe just about the strep for a minute, just about, I guess your perspective given what Shiranee was saying as well about antibiotics with Strep A. I know you're gonna say that if children are really sick, then they should definitely use antibiotics. That we, we've often taught about how lifesaving this is, but there obviously is an interesting balance and I think partly also, I'm hearing that potentially at times when it's very severe like now you might also, I think that's what I'm hearing from you, Shiranee, you're sort of, you would go to the antibiotics potentially sooner because of this level than, than elsewhere. But what are your thoughts? I think there are a lot of people, having read your books, all the rest of it, who are probably much more cautious about antibiotics than they would've been a decade ago.

[00:32:46] Tim Spector: Yes, so. For those who aren't aware there is this data showing that antibiotics are not harmless. You know, we thought they were this free magic bullet that really had no secondary effects that you could take them preventively for anything really, and they wouldn't do any harm.

But we know that in animals they've been used for the last 30 years to increase the growth of animals and the size of animals. And so they have been associated with increasing obesity. Lots of rodents studies showing that small doses of antibiotics or repeated doses can increase levels of body fat and the epidemiology around that, it does suggest it's not overwhelming, but it does suggest that there's a link in observational studies between kids that have large numbers of antibiotic courses and increasing allergies later in life. So these are not like you're bound to have allergies. These are relatively small increases, but more likely to have, problems with obesity or with allergies if you've had many antibiotic courses. But I'm absolutely not saying that if your kid has a very sore throat, a fever, feels unwell, give that kid antibiotics, you know, that's really important.

It's, oh well, someone in their class had a sore throat who was given it. I'm giving little Johnny the same thing. So I think it's where you draw the line, and I think this is where, you know, it gets really tough.

[00:34:22] Shiranee Sriskandan: So perhaps I can come in and talk a little bit about this. Yeah. You refer to mass use of antibiotics that, unfortunately I think the press has kind of somewhat over-egged that,

[00:34:32] Jonathan Wolf: And Shiranee, can you get a bit of context? Cuz not everyone I think…

[00:34:35] Shiranee Sriskandan: So there are two situations where the use of prophylaxis, so that's preventative antibiotics for people who are not ill at the moment, have been discussed. One is where there is a significant outbreak of scarlet fever in a school or a nursery, which is not being controlled by standard interventions.

So normally what happens when there's two kids in class with Scarlet Fever is the school's given lots of advice about hand and respiratory hygiene, about good ventilation, and making sure that any child who is diagnosed is given antibiotics and stays at home for at least 24 hours and all of the kinda usual stuff that they're told to do.

But sometimes it's just not possible to control the outbreak and you get more and more and more children in the class going down with infections. So it's been discussed in that setting now in the past. That has very rarely ever been done and it's only ever been done on a sort of single class basis 

When it's happened it has been effective in terminating the outbreak. Now what's the rationale for that? Well, we know cuz we've tested these kids in a previous year that actually, up to half the children in the class can be infected with exactly the same strain. They may not be ill with it, but they may be capable of transmitting it. And some of them do go on to become ill with it. So the rationale is, we know it is super infectious. It's at least as infectious as flu is.

[00:36:01] Jonathan Wolf: And Shiranee. I guess the real answer to this would just be to have a vaccine like we have developed for Covid and I understand this is something that you are actually working on.

[00:36:14] Shiranee Sriskandan: Well, I've, I mean, some people have been working with their entire careers and it's something that people were working on a hundred years ago and we have still not got one. And there's many reasons for that. One is that it is, it's a devious bug. It's so difficult for our immune systems to get over it, right, because it does everything in its powe to kind of wallop our immune system. So it's a very clever bug, and I've said this before, it's a proper pathogen, a card-carrying pathogen. You don't need just a little bit of immunity.

And it's, it's a bit more complicated than a virus. I mean, sorry, virologists out there.

[00:36:52] Jonathan Wolf: We don't want you to get your special battle now between, you know…

[00:36:56] Shiranee Sriskandan: sars cov2 is really simple compared with Group A Strep. I mean, he's got a 1,800 genes that can make proteins. So that's how many possible targets for a vaccine you might have to consider. But in reality, you know, we've had lots of ideas over the decades for how to vaccinate against this bug.

But it's been difficult and that's partly cuz it comes in over 200 different kind of flavors, types if you like. So that would be quite difficult for a vaccine to cope with. But there are other ideas, other ways of dealing with that.

[00:37:28] Jonathan Wolf: So it's not about to roll out next year, then Shiranee.

[00:37:31] Shiranee Sriskandan: Correct.

[00:37:33] Jonathan Wolf: Now to be clear,  I hated the lockdown. It was miserable for my mental health. But it is very interesting that in a sense we're suddenly paying attention to these things. And I know Tim talked about this through, the ZOE Health Study. So hopefully there will be some more silver lining out of this and more focus on these vaccines and everything else.

[00:37:53] Tim Spector: And our immunity maybe as well. You know, that's the other thing about how to protect ourselves against infections more and things that damage our immune system.

[00:38:03] Jonathan Wolf: I really wanted to finish with that actually, which is just, you know, a lot of people listening, we'd like to give some actionable advice and I think one thing I'd love to just discuss, maybe Tim, you could give us maybe three top tips for our listeners, like on what they could do if they wanted to boost their immune system. Try and keep safer and healthier this winter.

What would you be saying to them and, maybe also thinking about what you might be able to try and do with your kids, which I have to say is always a lot harder than things you want to do for yourself.

[00:38:32] Tim Spector: Yeah, I presume there’s not many two year olds listening to this.

[00:38:34] Jonathan Wolf: I suspect that they will have turned off this wonderful podcast some time ago.

[00:38:42] Tim Spector: So certainly for adults, we showed very nicely with over a million people that your diet has a big effect on your immune response to viruses. So actually having a diverse gut-friendly, plant rich diet low in ultra processed foods does have a demonstrable effect when you look at, you know, really big samples like that as we showed.

So we don’t know for sure, but we are assuming that is gonna be a similar effect on our immune reaction to other bugs, whether they're viruses or bacteria. So be able to suppress them early, stop them going on and lingering and causing other problems, I think is important. 

To have a really good functioning immune system, You need a good functioning gut microbiome. That's the community of microbes in your gut. And to do that, then you need this diverse, plant rich, high fiber diet that many of us have, have stopped eating as we've gone towards more and more ultra processed foods. So I think that's absolutely number one.

And diet is the main thing that everyone can do something about. They can make their food choices, and we believe that probably also applies to children. Over 70% of calories in children now come from ultra processed food in the UK and the US and that's getting worse. They harm the gut microbes, so giving them real food is really important.

More fiber. We think pets are important. Getting dirt is important. Getting kids playing in the soil, as long as it's not infected soil is a good thing. Walks in the forest, a smelly dog. All these things seem to give extra benefits for our gut health. And as well as, you know, don't take unnecessary treatments like antibiotics as we've discussed, when it's clearly a virus and it's self resolving.

So I think they're the three things. Diet. Getting dirty. And avoiding unnecessary antibiotics are my tips. We think that kids, particularly in the first five years of life, that's when their microbiome, which is gonna keep their immune system healthy, is forming. It's obviously the most crucial term to help them then.

And that's where we are letting them down, particularly diet-wise at the moment.

[00:41:06] Jonathan Wolf: That was brilliant, Tim. Shiranee and Tim, thank you so much for taking the time on this, like, I think very topical issue that a lot of people are, are really anxious about. I always try and summarize. Now I am absolutely not a doctor, so please correct me if anything here I say is wrong. I think the starting point that you all said is, if you have any concern with your child, of course you need to go and see a doctor and this podcast is not medical advice.

Having said that the first thing we said, Shiranee, I think you said was don't panic. So you know, keep this in its right place. There is much more strep probably than ever before and certainly much more than in the last few years. In terms of what you're looking for, this is very much, you're probably thinking about your children, although you did mention some people who may be in older age and their, their immune system may not be me so strong, but in your child, they're gonna be unwell.

They’re normally going to have a fever. They may complain of a sore throat if they're old enough to explain that. In some cases, they develop this wonderfully termed scarlet fever, which definitely makes me think of sort of 19th century novels and, you know, people in the Wild West. Sandpaper-y skin, if you are better than me at being able to tell the difference between the skin, and it's called scarlet fever.

But if your child has darker skin, you're not going to see that color. Shiranee is that right?

[00:42:26] Shiranee Sriskandan: Correct. Yeah.

[00:42:27] Jonathan Wolf: So, really the skin is what you'll see. I think you both said this wonderful thing of get to know the back of your child's throat, which no one has ever said to me before. I have no idea what the back of my children's throats look like, but I'm gonna go and have a good look later tonight.

And I think you said the big giveaway, if I understand on this, on strep, is you're gonna see these like giant tonsils with pus. And I assume that is not what I'm normally going to see if I look, is that right?

[00:42:54] Shiranee Sriskandan: Well, correct, but I mean, you need to kind of get looking, right? To know what your child’s throat normally looks like.

[00:42:58] Jonathan Wolf: I do. So I need to get the benchmark of not sick. Which is difficult because I think my daughter has literally been nonstop sick for the last six weeks. So actually quite hard to get. But I'm gonna try and see where it's smaller. So that will standardize.

[00:43:12] Shiranee Sriskandan: And remember, you might not see tonsils in the smaller kids.

[00:43:15] Jonathan Wolf: That's really helpful. So, so like do send in photos. So our social media is gonna be overwhelmed by tonsil pictures for the next week. So I think that will be quite fun. So do share. I think that'll be fascinating. That might be a whole future study. And in terms of antibiotics, I think Tim gave a very careful explanation and, and I think, you know, my summary was gonna be if your child is really sick, then get antibiotics.

If not, be aware that there can be some long-term negative impacts so be thoughtful. And we know that there are a lot of countries of which the US is probably at the top, but the UK is also quite high, where we can have a lot of overuse and we see this with some of our participants where they have a rather extraordinary number of courses of antibiotics through their life.

Brilliant. Thank you both so much. I really enjoyed this. I have learned a lot. It definitely makes me feel more relaxed than I was at the start of the podcast, which I think is fantastic. And I imagine that maybe a whole bunch of parents and grandparents who also feel that with this better understanding, they can be a bit more relaxed.

Thank you so much Shiranee for joining us, Tim, for joining us as you do so often. I hope you enjoyed yourself.

[00:44:27] Shiranee Sriskandan: Thanks very much. 

[00:44:28 ]Tim Spector:  Yep. 

[00:44:30] Jonathan Wolf: Thank you Shiranee and Tim for joining me on ZOE’s Science & Nutrition today. At ZOE, we want to improve the health of millions. If based on today's conversation you'd like to understand how to look after your health this season, you may want to try ZOE Personalized nutrition program. Your ZOE membership comes with our app and access to our nutrition coaches so you can learn how to change your diet and health habits and reach your long-term goals.

Your personalized nutrition program is based on our scientific research and the results of your personal at-home test. If you're interested in learning more about ZOE, you can head to and get 10% off your purchase.

If you enjoyed today's episode, please be sure to subscribe and leave us a review as we do love reading your feedback. If this episode left you with questions, please send them in on Instagram or Facebook and we will try to answer them in a future episode. As always, I'm your host, Jonathan Wolf. ZOE Science & Nutrition is produced by Fascinate Productions with support from Sharon Feder, Yella Hewings-Martin, and Alex Jones here at ZOE.

See you next time.