A short list of pathogens account for a large fraction of bacterial-related deaths. The main causes include S. aureus, E. coli, S. pneumoniae, K. pneumoniae, and P. aeruginosa.
These pathogen estimates are immediately relevant to groups concerned with the development of new antibiotics and new vaccines, such as research and development investment groups, the research authorities of different countries, and private sector investors in the pharmaceutical industry.
There may be a mismatch between R&D investment spending and disease burden. For example, $42 billion in the last two decades or so was spent on HIV, while the spend on a major bacterial pathogen like E. coli was only about $800 million. Yet the burden of E. coli is only a little bit smaller than the burden of HIV.
Prioritizing infection prevention is important through measures such as risk management, infection control in hospitals, and deploying existing vaccines (like the vaccine for Strep pneumo) more widely.
This transcript has been lightly edited for clarity
In this week’s Global Health Insights, we’re going back to the body of work that we started earlier this year when we published on the burden of disease due to antimicrobial resistance around the world, due to 88 bug-drug combinations. The big database that we put together on the distribution of key clinical syndromes – pneumonia, bloodstream infections, intra-abdominal infections, others. By pathogen, we have now analyzed, not looking for the resistance patterns, but just getting a deeper understanding of what the role of 33 different bacterial pathogens are in infectious disease deaths.
And that is really groundbreaking, because we tend to see in global health the burden of disease grouped by either some specific pathogens, like malaria, or syndromic clusters, like lower respiratory infections or neonatal sepsis or bloodstream infections. But by going in and looking at all the data, using the appropriate statistical methods that have been developed, to try to use all the rich data that’s out there to understand pathogen distributions, what we can reveal is the role of some bacterial pathogens that are probably hidden from people’s sight in the general global health discourse. So it turns out that as we look across pathogens, there’s a short list that accounts for a large fraction of bacterial-related deaths. So some of the main causes there are Staph aureus, E. coli, Strep pneumoniae, Klebsiella pneumoniae, and Pseudomonas aeruginosa, but also important roles for some of the other bacterial pathogens.
Research spending mismatch for bacterial pathogens
This pathogen view is important, and it’s immediately relevant to those groups who invest in research and development, the research authorities of different countries, NIH, for example, as well as to the investments from the private sector in the pharmaceutical industry, in the development of new antibiotics and new vaccines.
And in fact, there has been other research that’s been done that has tried to count in the last 20 years or so the spending on global pathogens. And when we compare that spend, for example, $42 billion in the last two decades or so for HIV, to the spending on some of these major bacterial pathogens like E. coli, that spend is only about $800 million. And yet the burden of E. coli is only a little bit smaller than the burden of HIV. And so I think this pathogen view of the world, or in this case bacterial pathogen view of the world, reveals that there may be a mismatch between how the R&D investments around the world in drugs and vaccines and diagnostics as well is not necessarily aligned with where all the burden is.
We also think it’s important to take a pathogen view of the world for thinking about prioritization around preventing infection where that’s possible through either risk management, infection control in hospitals, as well as deploying those vaccines that currently do exist, like the vaccine for Strep pneumo more widely. And of course, if we eventually do see new vaccines come through the R&D pipeline, recognizing that there is a real opportunity to reduce harm around the world.
Taking a pathogen-specific view on the burden of disease
So this focus on pathogens, in this case bacterial pathogens, comes out in our new paper in The Lancet. We do see further work in the future coming, looking at all of the pathogens together, not just the bacterial pathogens, to bring that pathogen-specific lens to the world. For about a quarter of all DALYs, a major pathogen is involved, whether it’s the ones that are directly assigned as underlying cause, like HIV or malaria, or the role of many of the things in this study, bacteria in deaths from some of the chronic diseases such as diabetes, where a diabetic may die from a gram-negative sepsis in the hospital.
But having that pathogen-specific view will give us another insight into the targets for intervention as well as for R&D. It also, I think, helps get a sense in different parts of the world of, we put a lot of emphasis, appropriately so, on HIV, TB, and malaria. But we probably need to pay as much attention to something that’s quite neglected, like Staph aureus, that’s affecting poor countries as well as rich countries.
And so I think there’s a lot to be learned about a different perspective on the burden of disease that’s brought about by this analysis. So expect more in our future Global Health Insights both on the sort of pathogen perspective, how does that look as we go into the future in terms of forecasting trends, given what we know is maybe some of the important changes in the disease profile in different parts of the world? And how do factors such as climate change intersect with the burden due to specific pathogens, that may actually be affected by environmental heat temperature and other factors? So more to come on these sort of evolving understanding of different drivers of burden around the world.
