The first in-depth global analysis of antimicrobial resistance (AMR) forecasts over 39 million deaths from infections by 2050 if more is not done to combat the problem. The global research team looked at data from over 200 countries between 1990 to 2021 to inform their modeling. 

“It is important to understand that AMR is not just a future problem; it is already a global crisis,” two co-authors of the paper – Tomislav Mestrovic, Affiliate Associate Professor at the Institute for Health Metrics and Evaluation (IHME); and Lucien Swetschinski, Research Scientist at the IHME – told IFLScience. “If left unchecked, AMR could reverse decades of progress in modern medicine.”

For all of us, that would mean a return to a time when a simple cut or scrape could lead to a life-threatening infection, not to mention the hugely increased risk that would come with invasive surgery or immune-modulating treatments like chemotherapy. Scientists have been raising the alarm about the so-called “antibiotic apocalypse” for decades now, but this new study took a very deep look at the problem.

“This analysis leverages millions upon millions of AMR data records to estimate the state of AMR in 204 countries and territories across 32 years (as well as forecasts until 2050),” Mestrovic and Swetschinski explained. Dealing with data of this magnitude and of variable quality was a considerable challenge – “akin to walking a tightrope,” Mestrovic and Swetschinski said. The team sought input from over 2,000 scientific experts to help inform the project, which has culminated in an author list that’s more than 500-strong.

Infections that are the most challenging for doctors to treat are becoming increasingly commonplace

Tomislav Mestrovic and Lucien Swetschinski

The data revealed that, from 1990-2021, more than a million people died every year as a result of drug-resistant infections. In the year 2050, the researchers forecast that this could increase to 1.91 million people. They also estimate that between now and 2050, AMR bacteria could play a role in up to 8.22 million deaths per year, an increase of almost 75 percent. 

“Infections that are the most challenging for doctors to treat are becoming increasingly commonplace,” Mestrovic and Swetschinski explained. Of the types of AMR bacteria that the World Health Organization is most worried about, all but one of them (Salmonella typhi) showed increasing mortality during the study period. 

“Another surprising aspect is the increasing role of AMR in sepsis-related deaths,” added Mestrovic and Swetschinski. “[A]lthough fewer people are dying from sepsis overall, those who do develop sepsis are increasingly likely to face infections that are resistant to treatment, making their outcomes worse.”

“Also, a striking finding from the study is a very evident rise in carbapenem resistance among Gram-negative bacteria, most notably Acinetobacter baumannii and Klebsiella pneumoniae.” Carbapenems are often the antibiotics doctors turn to as a last resort, so an increase in resistance to these drugs is alarming.

And there’s one more well-known bug that has come to particular prominence: methicillin-resistant Staphylococcus aureus, or MRSA. This ever-evolving bacterium is forever generating new strains that are often more infectious and more drug-resistant, making it tough to tackle both inside and outside of hospitals. 

Deaths associated with AMR will not hit all populations equally. During the 32-year study period, AMR deaths in children under five went down by 50 percent, and this trend is predicted to continue. On the flip side, deaths in those aged 70 or over have been increasing – and it’s thought that, by 2050, deaths in this age group could more than double. 

“As the global population continues to age, without more effective intervention strategies, we will see a dramatic rise in the AMR burden for this demographic group,” Mestrovic and Swetschinski told IFLScience. 

Some global regions will also be more affected than others. Between 1990 and 2021, five areas saw annual deaths increase by more than 10,000: western sub-Saharan Africa, tropical Latin America, high-income North America, Southeast Asia, and South Asia.

Individually, we can help reduce our personal risk of infection by only taking antibiotics when prescribed by a medical professional, practicing good hygiene, and staying home when sick

Tomislav Mestrovic and Lucien Swetschinski

But the message from the study authors is also one of hope. “The projections for 2050, which estimate millions of annual deaths due to AMR, are daunting, but they are not inevitable,” said Mestrovic and Swetschinski. “By increasing global focus on research, drug development, infection prevention and better patient care […] we can mitigate the worst outcomes.”

A key part of this will be finding new antibiotics, preferably ones that bacteria struggle to develop resistance to. This is a quest that has so far led scientists to some of the farthest reaches of our planet, from the deep ocean to inside the human nose.

Antibiotics are vital, but it’s equally important we don’t forget about other types of pathogens. A recent letter in The Lancet drew attention to the rise in drug-resistant fungi, and the threat these organisms also pose to human health.

Mestrovic and Swetschinski explained to IFLScience that “the development of new antifungal drugs has lagged behind the development of new antibiotics.” With fewer drugs to start with, and the difficulties in targeting fungi – fellow eukaryotes – without harming human cells, any increase in antifungal resistance is a concern.

It will come as no surprise to scientists that AMR is happening and is projected to worsen. Ideally, the results of this study will spark even greater efforts to combat this at a structural, population-wide level, but there are some things we can all do to have an impact.

“Individually, we can help reduce our personal risk of infection by only taking antibiotics when prescribed by a medical professional, practicing good hygiene, and staying home when sick,” Mestrovic and Swetschinski told IFLScience. Avoiding infection in the first place, through things like vaccination, safe food handling, and extra care when traveling, is also important.

AMR affects our animal friends too, so pet owners can work with their vet to ensure that all instructions around antibiotics are followed carefully. Any unused antibiotics – human or animal – need to be disposed of with care.

“And of course,” Mestrovic and Swetschinski added, “advocating for responsible antibiotic use is definitely a way we as individuals can help in combating AMR.”

The study is published in The Lancet.