More than 4.7 million deaths worldwide in 2021 were associated with drug-resistant bacteria, according to the World Health Organization, which adds that roughly 1 in 6 laboratory-confirmed bacterial infections around the world in 2023 no longer responded to antibiotics.
It is an odd outcome for a class of drugs that once looked like a clean win. Alexander Fleming was honoured with a Nobel Prize for penicillin, and at the Nobel Banquet on December 11, 1945 he warned his audience: “The time may come when penicillin can be bought by anyone in the shops.” Fleming understood that careless use would breed resistant microbes. Few listened, Quartz noted in its account of the problem.
Cheap drugs, heavy use
Farming changed the economics. In 1950, scientists at a New York laboratory found that adding antibiotics to livestock feed made animals grow faster. Combined with mass production, that made the drugs cheaper than the usual supplements. A study published in PNAS using 2010 data put global livestock use at more than 63,000 metric tons, with much of it in the developing world.
The mechanism is simple enough. Every dose gives bacteria a chance to mutate, and the more an antibiotic is used, the likelier it is that a resistant strain survives and spreads. The WHO lists inappropriate use among the main drivers, along with poor access to clean water, sanitation and hygiene, weak infection control in homes, hospitals and farms, and limited access to vaccines, diagnostics and medicines.
A last-resort drug under threat
One case showed how fast it can move. In November 2015, scientists in southeastern China testing bacteria from hospitals in Guangdong and Zhejiang provinces found a gene called MCR-1. It produces an enzyme that protects bacteria against colistin, a drug kept for cases where everything else has failed. Quartz reported that the gene had turned up in at least ten countries, including Canada, China and the United Kingdom, and that a study in The Lancet tied its appearance in part to farm use. About 12,000 metric tons of colistin went into animal production in the year before the report, with annual use forecast to reach 16,500 metric tons within five years.
Quartz, citing the US Centers for Disease Control and Prevention, said 23,000 Americans die each year from infections caused by resistant bacteria, against an estimated 700,000 deaths worldwide, and that the world could see 10 million by 2050 if trends held. The WHO’s later figure is far higher than that early 700,000 estimate.
The bill
The WHO puts the cost at US$ 412 billion a year up to 2035 for treating resistant bacterial infections alone, if action stays at today’s level, plus a further US$ 443 billion a year in lost productivity. Longer hospital stays and more intensive care drive much of it, along with greater reliance on second-line antibiotics and extra diagnostic testing. The agency also warns that too few new antibiotics are in development to replace those that stop working.
In May 2026 the World Health Assembly adopted an updated Global Action Plan on Antimicrobial Resistance covering 2026 to 2036.
Sources
- Superbugs are on track to kill 10 million people by 2050 if things don’t change—fast
- Antimicrobial resistance
- Antimicrobial resistance
