Nearly 40 million people could die from antibiotic-resistant superbug infections by 2050, new study finds

CNN
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The number of lives lost worldwide to infections resistant to drugs designed to treat them could increase by nearly 70% by 2050, according to a new study, further demonstrating the burden of the current superbug crisis.

In total, between 2025 and 2050, the world could experience more than 39 million deaths directly attributable to antimicrobial resistance or AMR, according to the study published Monday in the journal The Lancet.

Antimicrobial resistance occurs when pathogens such as bacteria and fungi develop the ability to evade the drugs used to kill them.

The World Health Organization has called AMR “one of the leading global threats to public health and development,” caused by the misuse and overuse of antimicrobial drugs in humans, animals and plants, which can help pathogens develop resistance to them.

The new study finds that when it comes to the prevalence of AMR and its impacts, “we expect it to get worse,” said lead author Dr. Chris Murray, director of the Institute for Health Metrics and Evaluation at the University of Washington.

“We need to pay particular attention to new antibiotics and their stewardship so that we can tackle what is actually a massive problem,” he said.

The researchers—from the Global Research on Antibiotic Resistance Project, the Institute for Health Metrics and Evaluation, and other institutions—estimated deaths and illnesses attributable to versus associated with antimicrobial resistance for 22 pathogens, 84 pathogen-drug combinations, and 11 infections in 204 countries and territories from 1990 to 2021. One death attributable to antimicrobial resistance was directly caused by antimicrobial resistance, while one death associated with AMR may have had another cause that was exacerbated by antimicrobial resistance.

Approximately 520 million individual records were used to make these estimates.

The researchers found that between 1990 and 2021, deaths from AMR decreased by more than 50% among children under 5 years old, but increased by more than 80% among adults aged 70 and older – trends that are expected to continue.

It’s been surprising to see these patterns emerge, Murray said.

“We have seen two opposing trends: a decline in AMR deaths among children under 15, mainly due to vaccination, water and sanitation programmes, some treatment programmes and their success,” Murray said.

“And at the same time, there is this steady increase in deaths among people over 50,” he said, as the world ages; older people may be more susceptible to serious infections.

The researchers found that the pathogen-drug combination that saw the largest increase in disease burden across all age groups was methicillin-resistant Staphylococcus aureus, or MRSA. For this combination — the antibiotic methicillin and the bacteria S. aureus — the number of attributable deaths nearly doubled, from 57,200 in 1990 to 130,000 in 2021.

Using statistical models, the researchers also produced estimates of deaths and illnesses attributable to AMR by 2050 under three scenarios: if the current climate continues, if powerful new antibiotics are developed to target resistant pathogens, and if the world has improved the quality of health care for infections and better access to antibiotics.

Projections show that deaths from antimicrobial resistance will increase by 2050 if measures are not put in place to improve access to quality care, powerful antibiotics and other resources to reduce and treat infections.

Researchers have estimated that by 2050, the number of global deaths attributable to antimicrobial resistance could reach 1.9 million, and those associated with antimicrobial resistance could reach 8.2 million.

According to the data, the regions of the world most affected by AMR and deaths from it are South Asia, Latin America and the Caribbean, and sub-Saharan Africa – and many of these regions do not have equitable access to quality care, Murray said.

“Unfortunately, there are still many places in low-resource settings where people who need antibiotics are just not getting them, and so that’s a big part of the reason. But it’s not just about antibiotics. It’s also about when you’re sick, whether you’re a child or an adult, and you’re sent to the hospital, and you’re given a package of care, essentially, that includes things like oxygen,” Murray said.

“In low-resource countries, even basic things like oxygen are often not available. And then if you’re very sick and you need an intensive care unit, well, there are large parts of the low-resource world – most of them, in fact – where you wouldn’t have access to that kind of care,” he said. “So there’s a whole range of supportive care, as well as antibiotics, that really make a difference.”

But in a scenario where the world had better health care, 92 million cumulative deaths could be prevented between 2025 and 2050, the researchers predict. And in a scenario where the world had new, more powerful drugs, about 11 million cumulative deaths could be prevented.

The study’s “innovative and collaborative” approach provides a “comprehensive assessment” of antimicrobial resistance and its potential burden on the world, Samuel Kariuki of the Kenya Institute of Medical Research wrote in a commentary accompanying the new study in The Lancet.

He warned, however, that the forecast models do not take into account the emergence of new superbugs “and could lead to underestimation if new pathogens emerge.”

Overall, “these data should spur investment and targeted action” to address the growing challenge of antimicrobial resistance in all regions of the world, Kariuki wrote.

The new paper represents decades of research on the global burden of antimicrobial resistance, said Dr. Steffanie Strathdee, associate dean of global health sciences and distinguished professor at the University of California San Diego School of Medicine, who was not involved in the study.

Strathdee saw firsthand the effects that antimicrobial resistance can have on health when her husband nearly died from a superbug infection.

“I am someone who has been living with antimicrobial resistance that has affected my family for eight years. My husband nearly died from a superbug infection. That’s actually one of the infections highlighted in this paper,” said Strathdee, who is co-director of the Center for Innovative Phage Applications and Therapeutics at UC San Diego.

In 2015, while on a Thanksgiving cruise on the Nile, Strathdee’s husband, Tom Patterson, suddenly developed severe stomach cramps. When a clinic in Egypt failed to relieve his worsening symptoms, Patterson was flown to Germany, where doctors discovered a grapefruit-sized abdominal abscess filled with Acinetobacter baumannii, a virulent bacteria resistant to nearly all antibiotics.

The annual number of people dying from Gram-negative bacteria, such as A. baumannii, that are resistant to carbapenems — a class of last-resort antibiotics used to treat serious bacterial infections — increased by 89,200 between 1990 and 2021, more than any other class of antibiotics during that period, the new study found.

“It’s one of the priority pathogens, which is one of these Gram-negative bacteria,” Strathdee said. “And my husband, when he got sick from this, was 69 years old. So he’s exactly at the age that this paper highlights, which is that older people are going to be more affected by this problem in the future, as our population ages and people have comorbidities, like diabetes, like my husband does.”

Strathdee’s husband recovered after treatment with phages, viruses that selectively target and kill bacteria and can be used as a therapeutic approach for antimicrobial-resistant bacterial infections.

“The most important alternative to antibiotics is phage therapy, or bacteriophage therapy, and that’s what saved my husband’s life,” Strathdee said. “Phages can be used very effectively with antibiotics, to reduce the amount of antibiotics needed, and they can even potentially be used in livestock and agriculture.”

The new study gives Strathdee hope that the world can reduce the potential burden of antimicrobial resistance. That would require improving access to antibiotics and new antimicrobial drugs, vaccines, clean water and other aspects of quality health care around the world, she said, while reducing the use of antibiotics in livestock, food production and the environment, which can breed further resistance.

“There may be hope on the horizon,” Strathdee said. “If we scale up these interventions, we could significantly reduce the number of deaths in the future.”