Antibiotics Use In Farm Animals Is Growing—Here’s Why It Could Pose A Danger To Humans

Topline

The global use of antibiotics and other antimicrobial drugs in animals will rise by the end of the decade, according to research published Wednesday in PLOS Global Public Health, a move that could help render the lifesaving drugs useless and accelerate the spread of hard-to-treat, resistant superbugs.

Key Facts

Some 107,500 tons of antimicrobial drugs—medicine used to kill or impede microorganisms including fungi, bacteria, viruses and parasites—will be used on farmed pigs, chickens, cows and sheep by 2030, researchers projected.

The figure, estimated using data on current trends, marks an 8% increase from 2020.

Agriculture uses the vast majority of the world’s antimicrobials—estimates put figures higher than 70%—and the projected jump comes despite global efforts to foster more responsible use of the drugs in a bid to curb the spread of resistant infections.

Antimicrobial resistance emerges when organisms like bacteria, fungi and viruses defeat the drugs used to treat them and it can make infections very difficult, or even impossible, to treat.

Farming often deploys the drugs—including many medically important ones like tetracyclines, amphenicols and penicillins—in healthy animals to keep livestock healthy and prevent disease, a strategy that helps promote resistance.

The researchers said China, Brazil, India, the U.S. and Australia are expected to retain their 2020 positions as the five countries using the most antimicrobials in 2030, having accounted for nearly 60% of global use at the start of the decade.

Key Background

Antimicrobials are among the most important tools in medicine. They are vital for treating a litany of infections, make invasive surgery possible and cut the risks of immune system-dampening treatments for conditions like cancer. Resistance threatens to wipe them out, possibly returning us to a time when now-easily treatable conditions—or even a papercut—can kill. A growing number of infections, including MRSA, gonorrhea, salmonellosis, tuberculosis and pneumonia are becoming harder to treat as the antibiotics used to combat them become less effective. The pipeline of new antimicrobials is weak, especially for new classes using new mechanisms to attack microbes, as there are few incentives for pharmaceutical firms to fund costly work in the field and resistance often emerges rapidly once a new drug hits the market. Health experts and agencies, including the CDC and WHO, describe the problem as one of the most pressing threats to public health facing humanity. In the U.S. alone, the CDC estimates there are more than 2.8 million antimicrobial resistant infections each year, killing more than 35,000. The agency puts the national cost of treating infections caused by the six superbugs commonly found in healthcare settings at more than $4.6 billion a year. Though the evolution of resistant superbugs is natural and expected over time, the misuse and overuse of antibiotics in both humans and animals is accelerating this process.

Surprising Fact

Profligate use of the drugs in agriculture, particularly to promote growth and prevent disease in healthy animals, is a key driver of resistance. In some countries, the sector is responsible for approximately 80% of total consumption for medically important antibiotics, the WHO estimates.

Big Number

10 million. That’s how many people will die each year from antimicrobial resistant infections by 2050, experts estimate. Most of these deaths are projected to be in poorer countries and many due to infections we could once treat.

What To Watch For

Experts warn the excessive and inappropriate use of antibiotics during the Covid-19 pandemic has erased years of progress combating antimicrobial resistance in countries around the world. In the U.S., the CDC estimates antibiotic resistant infections and deaths rose from 2019 to 2020, largely due to a 15% jump in infections acquired in hospitals. In a foreword to the report, agency director Dr. Rochelle Walensky described resistance as one of our “greatest public health concerns prior to the Covid-19 pandemic, and it remains so.”

What We Don’t Know

The nature of evolution and the biology of microorganisms, as well as its inherently global nature and intersection at numerous different areas of health, can make resistance hard to monitor and predictions on how it will emerge and spread difficult. Data suggests the scale of the problem may already be beyond the estimate of 10 million deaths by 2050. Some 1.27 million people died worldwide as a direct result of antibiotic resistant bacterial infections in 2019, according to a report published last year in the Lancet. The death toll—which only considers bacterial infections—is based on the most comprehensive estimate to date from before the Covid-19 pandemic. It already exceeds deaths from major killers like HIV/AIDS and malaria. Antimicrobial resistant infections played a role in an additional 5 million deaths that year, the report estimated.