Issue No. 16: Assessing the AMR Landscape — A Bird’s Eye View

In the world of antimicrobial resistance, 2022 began with an alarming bang. A cohort of international researchers, doctors, and scientists published a new estimate for the total number of worldwide deaths caused by drug-resistant superbugs. What they found confirmed what many experts already believed — that previous estimates have been woefully low, and the threat of AMR is much larger. Worldwide, over 1.2 million people died directly from a drug-resistant bacterial infection in 2019. And the researchers could associate AMR, at least partly, to a total of 4.95 million deaths that year. This shows that AMR is already one of the leading causes of death worldwide.

To put those numbers into perspective, that’s nearly 85% of the global deaths from Covid-19. One can see how AMR might soon reach pandemic levels.

The biotechnology industry continues to advance antimicrobial research and development. Members of the AMR Industry Alliance (AMRIA), which includes leading biopharmaceutical and biotechnology companies, injected between $1.8 and $1.9 billion dollars annually over fiscal years 2019 and 2020 into research and development. That’s crucial: In order to stop the death totals from reaching even higher, the world needs new antimicrobials to fight resistant infections. However, investment in this sector remains fragile, with investments expected to decrease if market conditions do not improve.

What follows is a bird’s-eye view of the most current data on the scale of the global AMR crisis, where the world stands in the fight against it, and solutions for the future.

A Sobering Conclusion

Publishing their findings in The Lancet, the researchers filled gaps in the pre-existing data. “To our knowledge,” they begin, “this study presents the most comprehensive estimates of AMR burdens to date.”

The study’s scope is vast. The collaborators looked at any deaths directly attributed to or associated with AMR from 204 countries and territories, many of which had not ever had estimates for AMR deaths. They also looked at 23 pathogens known to resist drugs, as well as 88 combinations of drug-specific resistant pathogens, like Methicillin-resistant Staphylococcus aureus (MRSA).

The researchers scoured available data sources, collecting “data from systematic literature reviews, hospital systems, surveillance systems, and other sources, covering 471 million individual records or isolates and 7,585 study-location-years.” They then used a statistical model to estimate total AMR burdens for every location.

Besides the topline numbers, researchers found which regions have the highest number of AMR deaths and also the specific bacteria with resistance that kill the most people. Sub-Saharan Africa had the most AMR deaths in 2019, with 23.7 per 100,000 people directly attributed to resistance. South Asia, which includes India, has the second-most at 21.5 deaths per 100,000 in population. They could attribute, or associate, most deaths to six resistant strains of bacteria, which accounted for 929,000 of the 1.27 million AMR deaths and 3.57 million of the 4.95 million associated deaths. Drug-resistant E. coliStaphylococcus aureus (MRSA), and two strains of pneumonia topped the list.

The Lancet study accounted for secondary AMR infections, which partly explains why it found a larger AMR burden than previous studies. 

People with injuries or diseases can wind up getting an infection — unrelated to their original malady — during or after medical treatment. This is known as a secondary infection. Surgeries to remove cancerous cells, replace knees, give birth, or really any operation could result in a secondary bacterial or fungal infection which can have resistance against common antimicrobial drugs. Those resistant infections can be deadly, but death certificates may not report them as the underlying cause of death. Instead, these deaths are typically attributed to the malady that initially brought the patient to the hospital, underrepresenting the real burden of AMR.

To account for secondary infections, the researchers counted any death where the underlying cause was infectious, or where sepsis — an organ failure due to an infection — was “the pathway to death” in cases of injury or non-communicable disease.

The Lancet statistical analysis sheds light on the issue on a previously uncharted global scale. The estimates for Sub-Saharan Africa, South Asia, Central Europe, Eastern Europe, and Central Asia — the regions with the most AMR deaths per capita — help put the scope of the crisis into perspective. And knowing which specific drug-resistant strains are the deadliest will help scientists more effectively combat AMR.

Compare The Lancet numbers to previous reckonings. The World Bank’s most recent global estimate puts AMR deaths at 700,000. Researchers at Washington University in St. Louis put the yearly U.S. death toll at 162,000, while the CDC directly attributed 35,000 annual deaths to AMR in the United States.

It’s understandable that these previous estimates undercounted AMR fatalities. But when accounting for new data sources and secondary infections, The Lancet analysis puts hard numbers to an intuition most close observers of the AMR crisis already know — superbugs are everywhere and killing more people than ever. Left unchecked, the global death toll from AMR could reach 10 million per year by 2050.

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