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  • October 2024

Antimicrobial Resistance (AMR): An update

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In Brief

At a high-level UN meeting on September 26, 2024, global leaders committed to a set of targets and actions to combat Antimicrobial resistance (AMR), which is associated with approximately 5 million deaths each year. In this follow-up to her original article on AMR, ¹ú±êÂ鶹ÊÓƵAPP Hilary Henly explains why insurers would be well served to monitor developments around this important health concern.

Key takeaways

  • Antimicrobial resistance (AMR) is a growing concern that is associated with approximately 5 million deaths each year. 
  • The COVID-19 pandemic accelerated the development of this concern. One new study estimates more than 8 million deaths each year could be associated with AMR by 2050. 
  • Because development of new antibiotics is proving challenging, disease prevention through measures such as vaccines will be key to fighting AMR going forward. 

 

Introduction

According to a 2019 analysis, an estimated 4.96 million deaths that year were associated with bacterial antimicrobial resistance (AMR), including 1.27 million deaths directly attributable to AMR.1 A new study estimates that by 2050, 8.22 million worldwide annual deaths could be associated with AMR, with as many as 1.91 million deaths directly attributable.2

During the 79th session of the United Nations General Assembly (UNGA79), the World Health Organization (WHO) and partners called on world leaders to address important global health challenges such as AMR. The recently published forecast indicates that, without any intervention to combat it, the AMR situation is likely to worsen. In response, proposed global targets for 2030 include achieving a 10% reduction in AMR deaths, a 20% reduction in inappropriate human antimicrobial use, and a 30% reduction in inappropriate animal antimicrobial use.3

At a high-level UN meeting on September 26, 2024, global leaders approved a political declaration committing to a set of targets and actions to combat AMR, which included the proposed 10% reduction by 2030 in the estimated 4.96 million lives lost to AMR annually. The declaration also called for financing to achieve a targeted minimum of 60% of countries having funded national action plans to combat AMR by that same year. It further added a target of at least 70% of antibiotics used for human health to be listed in the WHO AWaRe (Access, Watch, Reserve) antibiotic book,4 which classifies antibiotics into three groups:

  • Access antibiotics: those antibiotics with a narrow spectrum of activity, low cost, and generally low-resistance potential.
  • Watch antibiotics: a broader-spectrum antibiotic associated with a higher level of resistance potential. They have a higher cost and are recommended as first-choice options only for patients with more severe infection.
  • Reserve antibiotics: a last-choice antibiotic used to treat multi-drug-resistant infections.

Other targets included providing basic water, sanitation, and hygiene (WASH) to all healthcare facilities in 100% of countries. Further commitments around access and appropriate use of antibiotics included their use in the agricultural sector.

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Trends in antimicrobial resistance 

AMR is a leading cause of mortality globally, accounting for approximately 9% of all deaths. An estimated 36 million lives have been lost to AMR since 1990, and it is projected that another 39 million lives will be lost between 2025 and 2050.2 Those most at risk from AMR death include children younger than 5, adults older than 65, and immunocompromised patients.5

The six leading bacterial pathogens accounting for 73% of AMR-related deaths in 2019 were:

  • Escherichia coli 
  • Staphylococcus aureus
  • Klebsiella pneumoniae 
  • Streptococcus pneumoniae 
  • Acinetobacter baumannii
  • Pseudomonas aeruginosa 

These same six pathogens had the highest AMR burden of at least 100,000 deaths each in 2021.2 All six are included in the 2024 WHO Bacterial Priority Pathogens List, which covers 24 pathogens across 15 families of antibiotic-resistant bacterial pathogens, grouped into critical-, high-, and medium-priority categories. The list is designed to help guide research, drug development, and strategies to prevent and control AMR. Gram-negative bacteria, such as Acinetobacter baumannii, which are resistant to last-resort antibiotics, are listed as a critical priority because of the general severity of the infections and their significant global burden on health.6

The most recent 2024 analysis of the global burden of bacterial antimicrobial resistance for 1990 to 2021, with forecasts to 2050, is based on 22 pathogens, 84 pathogen-drug combinations, and 11 infectious syndromes in 204 countries. It looks at the proportion of infectious deaths associated with a drug-resistant infection, and deaths attributable to the drug resistance of an infection.

Researchers estimated that 4.71 million deaths were associated with bacterial AMR in 2021, including 1.14 million deaths attributable to bacterial AMR. While deaths from AMR decreased by more than 50% in children younger than 5, they increased by more than 80% in adults 70 and older. Global deaths from Staphylococcus aureus increased the most, but gram-negative bacteria resistance to carbapenems, considered a last-resort antibiotic, increased more than for other antibiotic classes.2

From 2022 to 2030, global deaths from AMR are forecast to increase 13.4% to 1.28 million, and to increase 69.6% by 2050.2 In 2022, 236 million outpatient antibiotic prescriptions were dispensed in the US, a prescription rate of 709 per 1,000 population. This is an increase from 636 per 1,000 in 2021.7 A recent review found that 63.4% of antibiotics dispensed from community pharmacies worldwide were without prescription.5

Under a better care scenario, where improved healthcare quality for infectious syndromes and access to antibiotics would lead to decreases in both AMR burden and infectious burden not associated with AMR, an estimated 92 million deaths could be avoided between 2025 and 2050. Developing new potent gram-negative drugs alone could prevent an estimated 11.1 million AMR deaths over that same period of time. The increasing mortality rate from carbapenem-resistant Acinetobacter baumannii is extremely concerning; thus, the development of new gram-negative antibiotics to help reduce mortality rates would be highly impactful.2

Antibiotic use during the COVID-19 pandemic

From March to October 2020, nearly 80% of patients hospitalized with COVID-19 received an antibiotic. The COVID-19 pandemic accelerated the use of antibiotics and subsequent pathogen resistance, particularly carbapenem-resistant Pseudomonas aeruginosa, in the US. In carbapenem-resistant K. pneumoniae, A. baumannii, P. aeruginosa, and Enterobacter spp., mortality is more than 30%.6

The US Centers for Disease Control and Prevention (CDC) recently reported that bacterial AMR hospital-onset infections caused by six common pathogens found in healthcare settings increased overall by 20% during the pandemic, compared with 2019. Studies show a large increase in resistant infections acquired during hospitalization from 2019 to 2020 for eight different pathogens:8,9

  • Carbapenem-resistant Acinetobacter (+78%)
  • Antifungal-resistant Candida auris (+60%)
  • Carbapenem-resistant Enterobacterales (+35%) 
  • Antifungal-resistant Candida (26%) 
  • ESBL-producing Enterobacterales (+32%)
  • Vancomycin-resistant Enterococcus (+14%) 
  • Multidrug-resistant Pseudomonas aeruginosa (+32%) 
  • Methicillin-resistant Staphylococcus aureus (+13%)

Tackling AMR

The development of new antimicrobials has been slow, as it has proven difficult to find new substances effective in treating bacterial infection. Since 2010, 29 antibiotics received marketing authorization, but most were modifications to existing antibiotics.5 In June 2024, the WHO reported on the clinical pipeline for antibacterial products up to December 2023. Of the antibacterial agents in development, 38 were in Phase III trials.10 New treatments such as the use of phages (viruses that infect bacteria) are in development, and research into the use of monoclonal antibodies in the treatment of microbial infections is growing.5

However, preventing infections through existing measures such as vaccination and improved access to WASH, particularly with increased antibiotic use in low-income settings, is key. Timely and accurate diagnosis of infection is imperative for reducing inappropriate antibiotic use and resulting AMR. Vaccines can help prevent infections from ever occurring, eliminating the need for first- and second-line antibiotics, thereby reducing the emergence of drug-resistant bacteria.

While healthcare systems take on this challenge, the implications for life and health insurers will be significant. On the health side, for example, as more people are exposed to antimicrobial-resistant organisms, an increasing number of patients, particularly the elderly, will require extensive long-term hospital care before they either are successfully treated or succumb to infection. Resulting healthcare costs are likely to rise significantly, much of which may be covered by insurance. 

For life insurers, underwriters and claims assessors are more likely to see cases with a history of second- and third-line antibiotic treatment and sepsis/organ function impairment. Over time, a higher proportion of global deaths may be attributed to AMR, affecting mortality rates in both low- and high-income countries. Insurers will need to assess these trends as they develop long-term mortality and morbidity assumptions. 

Conclusion

AMR is increasing rapidly in all parts of the world, leading to higher mortality, particularly for those older than 70. Without immediate action, the targets set by UNGA79 regarding AMR will be difficult to achieve. Progress on AMR will require faster and improved drug development, improved infection prevention, wider population vaccination, earlier identification and treatment of infections, and reduced rates of inappropriate antibiotic use.


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Meet the Authors & Experts

Hilary Henly
Author
Hilary Henly
Global Medical Researcher, Strategic Research 

References

  1. axminarayan, R. (2022). The overlooked pandemic of antimicrobial resistance. The Lancet, Feb 2022; 399(10325): 606-607. Available from: The overlooked pandemic of antimicrobial resistance - The Lancet
  2. GBD 2021 Antimicrobial Resistance Collaborators (2024). Global burden of bacterial antimicrobial resistance 1990-2021: a systematic analysis with forecasts to 2050. The Lancet, 2024 Sept 13: S0140-6736(24)01867-1. Available from: Global burden of bacterial antimicrobial resistance 1990–2021: a systematic analysis with forecasts to 2050 (thelancet.com) 
  3. Mendelson, M. et al. (2024). Ensuring progress on sustainable access to effective antibiotics at the 2024 UN General Assembly: a target-based approach. The Lancet 2024; 403: 2551-64. Available from: Ensuring progress on sustainable access to effective antibiotics at the 2024 UN General Assembly: a target-based approach (thelancet.com)
  4. WHO (2024). World leaders commit to decisive action on antimicrobial resistance. Joint News Release 26 September 2024. Available from: World leaders commit to decisive action on antimicrobial resistance (who.int)
  5. Ho, C.S. et al. (2024). Antimicrobial resistance: a concise update. Lancet Microbe 2024; 100947. Available from: Antimicrobial resistance: a concise update - The Lancet Microbe
  6. WHO (2024). WHO Bacterial Priority Pathogens List, 2024: bacterial pathogens of public health importance to guide research, development and strategies to prevent and control antimicrobial resistance. Geneva: World Health Organization; 2024. Available from: 9789240093461-eng.pdf (who.int)
  7. CDC (2024). Antibiotic use and stewardship in the United States, 2023 update: progress and opportunities. Antibiotic prescribing and use, April 22 2024. Available from: Antibiotic Use and Stewardship in the United States, 2023 Update: Progress and Opportunities | Antibiotic Prescribing and Use | CDC 
  8. CDC (2024). Antimicrobial resistance threats in the United States, 2021-2022. Available from: AR Threats Report (cdc.gov)
  9. CDC (2022). COVID-19 US impact on antimicrobial resistance. 2022 Special Report. Available from: 2022 SPECIAL REPORT: COVID-19 U.S. Impact on Antimicrobial Resistance (cdc.gov)
  10. WHO (2024). Clinical pipeline analysis for antibacterial products, trends from 2017 to current. Available from: Trend analysis of antibacterial agents in the pipeline (2017 - 2023) (who.int)