The Slow Pandemic: Antimicrobial Resistance in Numbers

Antimicrobial resistance is sometimes called a slow pandemic. A crisis that lacks the sudden visibility of an outbreak but accumulates deaths at a pace that rivals the world’s leading killers. The most comprehensive accounting to date, published in The Lancet in 2022 and drawing on data from 204 countries, found that drug-resistant infections were directly responsible for 1.27 million deaths in 2019 and were associated with 4.95 million deaths in the same year, a figure that approaches the annual toll of HIV/AIDS and malaria combined. Unlike most infectious disease threats, AMR does not arise from a single pathogen. It is a property that spreads across bacterial species, a consequence of evolutionary pressure applied whenever antibiotics are used and increasingly, wherever they are overused.

The geographic burden is concentrated but not confined to low-income settings. Sub-Saharan Africa carried the highest mortality rate attributable to AMR at roughly 24 deaths per 100,000 population. South Asia was second. High-income countries reported approximately 13 deaths per 100,000 a lower rate but an enormous absolute toll given population size. Six pathogens accounted for the majority of AMR deaths globally: Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, Streptococcus pneumoniae, Acinetobacter baumannii and Pseudomonas aeruginosa. Lower respiratory infections were the syndrome most commonly involved and carbapenem resistance; resistance to the antibiotics used as last-resort treatment; was a defining feature in the most lethal cases.

The pipeline problem compounds the mortality picture. Antibiotic discovery essentially stalled after a productive period in the mid-twentieth century. The last genuinely new class of antibiotics to reach clinical use against Gram-negative bacteria entered the market in the early 1960s. As of the WHO’s most recent pipeline review, roughly 43 antibiotics were in clinical development globally, but the majority were modifications of existing classes rather than novel mechanisms of action. Fewer than a dozen candidates in the entire pipeline represented new chemical classes. Meanwhile, resistance to existing drugs continues to spread. The WHO classifies Acinetobacter baumannii resistant to carbapenems as a critical-priority pathogen, yet no approved treatment specifically designed to address it has reached the market.

Agriculture is the largest single consumer of antibiotics by volume on the planet. Estimates consistently place the share of medically important antibiotics used in food-producing animals at 70% or more of global consumption. In the United States, FDA data have shown that the volume of medically important antibiotics sold for use in food animals dwarfs the volume used in human medicine. Resistance genes move from livestock environments into soil and water and, from there, into the bacteria that infect people. A projected 67% increase in global agricultural antibiotic use between 2010 and 2030, driven largely by rising meat demand in middle-income countries, makes the environmental reservoir of resistance genes a structural feature of the problem rather than an edge case.

In the United States, the CDC estimates that drug-resistant bacteria and fungi cause at least 2.8 million infections and more than 35,000 deaths each year. Methicillin-resistant Staphylococcus aureus (MRSA) alone accounts for approximately 10,000 deaths annually. Drug-resistant tuberculosis, a separate but related front, produced an estimated 450,000 new cases of rifampicin-resistant TB globally in 2023 according to the WHO, with roughly 187,000 deaths. Treatment for drug-resistant TB requires drugs that are more toxic, far more expensive and administered for up to 20 months, compared to the standard six-month regimen for drug-susceptible disease.

The economic projections, while inherently uncertain, are sobering. The landmark O’Neill Review commissioned by the UK government in 2016 projected that AMR could kill 10 million people per year by 2050, surpassing cancer, and impose cumulative global economic costs of $100 trillion over that period. Even in the near term, the CDC estimates AMR generates over $20 billion in excess direct healthcare costs in the United States annually and a further $35 billion in lost productivity. These costs fall disproportionately on patients requiring intensive care, on immunocompromised populations and on health systems in low-income countries that lack the infrastructure to contain resistant organisms once they circulate.

What makes AMR tractable, in principle, is that it is not a random natural event but a largely predictable consequence of how antibiotics are prescribed, sold, used in agriculture and sterilized in hospital environments. Stewardship programs that restrict unnecessary prescribing, investment in diagnostic tools that distinguish bacterial from viral infections and regulatory incentives for antibiotic development have all demonstrated measurable impact where they have been seriously implemented. The gap between what is technically achievable and what is happening in practice remains very wide.

Key Numbers at a Glance

Top Six AMR Pathogens by Global Mortality (2019)

WHO Critical-Priority Resistant Pathogens

Drug-Resistant Tuberculosis Trend

US AMR Burden (CDC Estimates)

Sources: Murray et al., “Global burden of bacterial antimicrobial resistance in 2019: a systematic analysis,” The Lancet (2022); CDC Antibiotic Resistance Threats in the United States (2022); WHO Global Antimicrobial Resistance and Use Surveillance System (GLASS); WHO Global Tuberculosis Report 2024; O’Neill Review on Antimicrobial Resistance (2016); WHO Antibacterial Pipeline Review (2022); FDA National Antimicrobial Resistance Monitoring System.