AMR is a major threat to global health

Three deaths every minute—that’s the number of people estimated to die between 2025 and 2050 from AMR, or antimicrobial resistance. The latest Global Burden of Disease Study (GBD) study on AMR is the most comprehensive to date. It looks at what’s driving AMR trends, which groups are impacted the most, and what can be done to address this major global health threat. We discuss the data with study author IHME Director Dr. Chris Murray.

This transcript has been lightly edited for clarity

Rhonda Stewart: Welcome to Global Health Insights, a podcast from IHME, the Institute for Health Metrics and Evaluation. I'm Rhonda Stewart. In this episode, we'll hear from IHME director Dr. Chris Murray as he discusses the most comprehensive study yet to examine the global burden of antimicrobial resistance, or AMR, through the year 2050. These scenarios provide information in the present that can help shape the future. The research is part of the Global Burden of Disease study, also known as GBD. GBD is the largest and most detailed scientific effort undertaken to quantify health trends. GBD provides a unique platform to compare the magnitude of diseases, injuries, and risk factors across age groups, sexes, countries, regions and time. For decision makers, GBD provides a unique way to compare countries' health progress and to understand factors that impact health, such as high blood pressure, cancer, and heart disease. Led by IHME at the University of Washington, GBD is a truly global effort, with more than 12,000 researchers from over 160 countries and territories participating in the most recent update. The latest GBD studies cover topics including fertility, health forecasts, and risk factors to health. 

Chris, why is antimicrobial disease, or AMR, such a threat to health? And how does this study go beyond previous research on the burden of AMR?

Dr. Christopher Murray: So the previous global effort on the burden of AMR, which came from our group with our collaborators in Oxford and elsewhere, was a single cross section. It was assessing the burden of AMR in 2019. And everybody wants to know, is AMR getting worse or better? You know, in which parts of the world? What are the time trends? And so we've had a major effort to try to understand what's the trends in AMR back to 1990. And that's what this study does for the first time, it looks at all the data and says, what's been happening to AMR by age, by sex, by pathogen, by country. And so it's a very important step in understanding the direction for this major global problem.

Rhonda Stewart: And in looking at the direction of AMR and where it's headed to, what are you seeing in terms of AMR as a threat to health?

Dr. Christopher Murray: So the findings are pretty interesting and take some time to make sense of, if you look at the most aggregate measure deaths attributable to AMR, it's pretty flat. It's a pretty flat line, about 1.2 million up and down a little bit, but it's surprisingly flat. But if you dig into that a little bit, you find out that that flat line at the global level is masking two opposite trends. The number of deaths under age 15 attributable to AMR has been dropping very steadily over the last 30-32 years. And that decline is all about preventing infection. It's vaccination, it's better water, better sanitation, a little bit better access to antibiotics, treatment for pneumonias. And it goes along with this extraordinary global health success, which is the 50% reduction in child death rates that we've seen over that time period around the world. So you have that decline, but at the same time, the number of deaths attributable to AMR over age 50 has been going up very steadily. And part of that is that in those older age groups, fifties, sixties, seventies, and older, at much greater risk of severe infection, going to the hospital, perhaps getting a drug resistant infection in hospital. And so we just see more AMR infections, more AMR deaths in those older age groups. And as the world ages, we get more and more people in those age groups. And so, not surprisingly, we're seeing this really marked increase in the older ages. So two very different trends, and then that translates into a different story, into the future.

Rhonda Stewart: And the study looks at trends going out to 2050, and it includes a reference forecast, which is the most likely future, and alternative scenarios. And so what are the main findings for the reference forecast?

Dr. Christopher Murray: Well, it's running those trends I was describing out into the future. So there's less room for declines in AMR in children, partly because child death rates have come down a lot already. And there's a lot of scope for more deaths over age 50 because of the huge demographic aging that's occurring in the world, there's just an explosion of people in the over 50 age group that we expect to see. And so that means we expect AMR overall to go up, deaths from AMR. Now, we also like to look at measures like disability-adjusted life years or years of healthy life lost. And in that metric, although deaths are gonna go up because there's more DALYs lost per child death than there is for a death over 50, the DALYs in the future don't go up as much as we see this big increase in the number of deaths attributable to AMR. And that's the reference scenario. There's lots we can do to alter that future by investing in the pipeline for R&D, so that we have more antibiotics that work against the major infections, or we just increase access to the poor and disadvantaged and excluded around the world, so that we just generally improve the outcomes for infection around the world. Either of those or both together make a really big difference to this trajectory.

Rhonda Stewart: And you've talked about some of the trends with respect to different age groups. What about some trends at the location level? What are you seeing there?

Dr. Christopher Murray: So everyone imagines that AMR is a rich person or rich country problem. But what we showed for the 2019 study, and again, we see in this study is that's actually not the case. There's more infection in poor places, more pneumonias, more diarrhea, more meningitis. And that trend means that even though the percent of each infection that has a drug resistant bug may be slightly lower than in a rich country, in total the burden from AMR in poor places, particularly sub-Saharan Africa, South Asia, is largest in those parts of the world and not in the high-income world.

Rhonda Stewart: What types of interventions can be implemented to address the burden of AMR and what gives it, what makes so much, brings so much urgency to the need to address the burden of AMR?

Dr. Christopher Murray: So the set of things that we can do are around antibiotic stewardship, so making responsible use of the antibiotics that we have so that we don't cause greater amounts of, or select for more resistance by using antibiotics inappropriately. We have a series of interventions, strategies that can be used to address AMR. First is antibiotic stewardship, that is, the responsible use of antibiotics when people need them and not excess use when they don't need them. So we stop selecting for drug resistant bugs. Secondly, we need a robust pipeline, because when we use antibiotics, even responsibly, we will see resistance levels go up. And the way to counter that is to invest in the development, the research and development needed to make new classes of antibiotics. And so a robust antibiotic pipeline is super important. A third one is just reducing expo, you know, the number of infections in the world, the way we brought down AMR in children more generally. So that's vaccination strategies, you know, that's hospital infection control. That is, you know, the other types of risk interventions that affect infections, whether it's air pollution or household air pollution. A long list of strategies to reduce infections. And then the fourth one there, that's a little is common sense, makes, you know, we all are worried about the science needs to be strengthened, but it's the link between antibiotic use and the food supply in the agricultural sector into humans. You know, that seems like it's a real threat, a real risk. The evidence is not as compelling, because we just haven't put it all together. But it makes a lot of sense for us to also have a One Health approach to AMR.

Rhonda Stewart: And then looking at the different things that the private sector can do to address AMR and then things that policymakers can do, what might be one important thing for each of those groups to focus on?

Dr. Christopher Murray: Well, the private sector has a huge role to play in, especially the research part of the pharma sector, in producing, doing the research and producing new antibiotics. They're a critical component of R&D for the future. They've also played an important role in helping us understand how much AMR there is out there, because this is a case where the private sector, whether it's pharmaceutical or the diagnostics companies, have been critical in collecting some of the richest data sets to track the spread of AMR. So it's another important role that the private sector can continue and also just delivering low cost antibiotics around the world to those who need them through efficient production and distribution. And on the policy side, it's about encouraging antibiotic stewardship. It is about government surveillance systems and of course, the research arm, the NIH type examples around the world of investing in the basic and applied research that's going to help us see new antibiotics delivered.

Rhonda Stewart: Finally, what's the main thing that people should take away from this comprehensive data?

Dr. Christopher Murray: The main thing is that AMR is a really big problem. It is up there with the problems that global health tends to spend a lot of time worrying about: TB, HIV, malaria. It's actually larger than each of those. It is not a problem that's going away. It's actually spreading and likely to get worse in the older age groups. And it requires action to avoid it being even worse than what we're saying in the reference scenario. Because certainly if we don't invest in new antibiotics and run out of the antibiotics that we currently have, or resistance gets to such a level that they're not particularly useful, things could be much worse than what we say in our reference scenario.

Rhonda Stewart: Thanks very much, Chris. Details about the Global Burden of Disease study and a wide range of GBD-related resources can be found at healthdata.org.