The rise of superbugs: what is antimicrobial resistance?

Today, we’re tackling a silent pandemic: it’s Antimicrobial Resistance, or AMR. Every year, millions of infections become harder to treat as microorganisms evolve to resist the medicines we normally use to fight them. I’ve still got the guidelines issued to me as a junior doctor, explaining what antibiotic to give for what infection. But when I looked at it again the other day, two decades after I last used it, I made the shocking realisation that many of the drugs on that list would not work reliably these days for the infections we were writing them up for back then. The bugs are all becoming resistant. And that’s just over the last 20 years. Moreover, there are almost no new antibiotics entering the market to replace those agents we’ve lost. As a result, many clinicians are extremely worried that we’re sleepwalking into a silent pandemic of epic proportions where even mundane infections can become lethal again like they were 100 years ago. So what can we do to stay one step ahead? I’ve been down to University College London to meet members of their new Digital Health Hub for Antimicrobial Resistance, which is seeking to tackle the problem. Laura Shallcross is the director of UCL’s Institute of Health Informatics…

Laura - AMR stands for antimicrobial resistance. Microbial is just a complicated way of saying different kinds of bugs, viruses, bacteria, parasites. And what the resistance bit means is we've got drugs that are used to treat those bugs, to treat those kinds of infections, but they aren't working as well. And so resistance is when an antibiotic that you rely on to treat bacteria doesn't do its job anymore.

Chris - Is this a recent phenomenon?

Laura - It really isn't a recent phenomenon. So we know way back when antibiotics were discovered by Fleming, he at the time said, we need to be really careful here because there's a massive risk if we use these drugs in the wrong way, we're going to end up developing lots of resistance. And that is exactly what has happened. But the new part now is that we used to be in a lucky position where every time we got resistance to a bug, we were able to find a new antibiotic. But for some time now, that pipeline of new antibiotics has really dried up. And so it means that we're running out of effective medicines. And that's a problem for all of us in lots of different ways.

Chris - Is it drying up because pharmaceutical companies have run out of ideas? Or is it drying up because they don't make as much money doing that? So they've turned their attention to look at other things?

Laura - That's a good question. So there's definitely something around the cost of developing new drugs, and about the incentives to invest in developing antibiotics. And what people often talk about is that if we get a new antibiotic, people want to put it in a cupboard, lock it away, don't let anyone use it. So why, as a pharmaceutical company, would you spend all that money inventing a new one? And so there are all sorts of perverse incentives that make it difficult to get new drugs to market. And it's difficult. I think we've been through the ones that were easier to discover, and now it's definitely harder.

Chris - Where does the whole resistance stem from in the first place?

Laura - So lots of people think that it's our bodies that get resistant, and it isn't. It's the bugs. So they evolve, and they evolve, and this is just something that they do. And as they evolve, they mutate, and they can learn how to become resistant to different kinds of antibiotics or antimicrobials. So the challenge is we can't really stop that process from happening. We have to respond to it, and that's why we need lots of different strategies to tackle AMR.

Chris - And can, if one group of microbes develop resistance, can they share the knowledge? So one bacterium has it, but can it give it to its mate that is a totally different kind of bacterium?

Laura - Yeah, absolutely. So these things work differently for different kinds of bacteria, but yes, absolutely, they're able to share genetic material between bacteria, and so to transfer those different ways of evading antibiotics, and so those traits spread.

Chris - What's our best strategy then for fending off the problem?

Laura - So there are lots of different things that are being tried, and the strength of evidence to support different approaches is variable. What everybody agrees on is that being more careful about how we use antibiotics is really important, because we know from how those bacteria evolve, if we use lots of antibiotics, it promotes the emergence of antimicrobial resistance. So if we use antibiotics more sparingly, that is a way of trying to preserve the ones that we've already got.

Chris - But if you've got an infection, you've got an infection.

Laura - And that's true. But sometimes people have viral infections that don't respond to antibiotics, and they get antibiotics anyway. And there's also a lot of ongoing uncertainty about the best way to use those antibiotics. So it used to be that we would use antibiotics for long courses, so maybe you treat somebody for seven days, and now there's much better evidence that actually you can treat say for three days. So we're really trying to learn about how we can maximise the use of these valuable drugs, but also minimise those harms and potential side effects.

Chris - Are there any hot spots where this is particularly a problem? Is it just a problem for hospitals? Is it a problem in the community? Are there some countries where this is a major problem, and those are the ones to watch?

Laura - So there are definitely areas of the world where we see higher rates of drug resistant infection for sure. Countries in Southeast Asia, for example. But it all partly depends on how much surveillance, how much testing and sampling you're doing, which makes it hard to get a very accurate sense of the prevalence of drug resistance across different countries. What is probably fair to say is that you see the impact of this at the severe end of the spectrum. So for example, if you're somebody who's had an organ transplant, you desperately need antibiotics to be able to survive that process. If you don't have access to those antibiotics, you could die, you could very easily die. So I think that many of us may be using antibiotics inappropriately, so we're all part of it, but actually the impact of it is seen in those most vulnerable groups.

Chris - If we carry on the way we're going, what does the future look like?

Laura - So I remember when Dame Sally Davis started really raising this as an issue going back over 10 years now.

Chris - Yes, she was our Chief Medical Officer. She made this very much her mission, didn't she? She famously said the threat is bigger than the threat from terrorism.

Laura - Yeah, and got it included on the risk register and so forth. So yeah, absolutely. And I think that the problem we've got is antibiotics underpin so much of care. So we have the example we're all familiar with. You go to the GP, you get an antibiotic, fine. But as I said about the transplant example, or if you're going in to have surgery in hospital, caesarean sections, or you get bitten by, let's say you get an insect bite and it becomes a skin, a deep skin infection, you need antibiotics. None of these things sound serious or scary until you think, well, what would happen if actually I couldn't get treatment for that and it got worse and it turned into a bloodstream infection? And if you sort of follow that thought process, you get to a place where medical procedures, the way that we have medicine now, doesn't work anymore. And it's a bit like going back in time where you get an infection, or maybe you die, or maybe you end up losing a limb, or that might sound a bit dramatic.

Chris - Is this a realistic prospect, Laura? Or is that sort of catastrophising and saying, this is the worst that could happen, but actually it probably won't?

Laura - I think that the risk here is that we sleepwalk into a situation like that because we keep thinking, oh, well, our antibiotics work. It's definitely a possible outcome. Yeah. I mean, we, you know, there are certain patients where if they don't have access to antibiotics, the outcome will be absolutely catastrophic. You may be fine with your cold in primary care, but if you have sepsis in hospital and you actually need antibiotics and the right antibiotics, that's not a good outcome. That's not where you want to be.