In his 1941 novel The Library of Babel , Jorge Luis Borges imagines a universe made entirely of books - every possible 410-page combination of 22 letters, a period, a comma and a space. Somewhere within are all the meaningful works ever written, but the vast majority are nonsense.
Author
- Gianni Lo Iacono
Senior Lecturer in Biostatistics and Epidemiology, School of Veterinary Medicine, Faculty of Health and Medical Sciences, University of Surrey
That's how it felt when our team began a systematic evidence map on antibiotic resistance , screening over 13,000 manuscripts to find the few relevant ones to our scope. All solid research, but it was a number that could make even our most enthusiastic collaborators go pale. We were wandering our own virtual Babel. The scale reflects the urgency of tackling antimicrobial resistance (AMR) - a global threat to human health, food security and agriculture that could cause 10 million deaths annually by 2050 , outstripping cancer's current toll of 8.2 million.
The long fight against resistance
Focusing on antibiotics, Nobel laureate Selman Waksman defined them as "a compound made by a microbe to destroy other microbes" . Humans have understood and used this principle for millennia, from applying mouldy bread poultices to wounds to the antibiotic "golden age" of the 1940s-1960s, when an explosion of new drugs fuelled optimism that infectious diseases might soon be a relic of the past in high-income countries.
This was the era that spawned the much-repeated (and much-misquoted) declaration attributed to US Surgeon General Dr William Stewart: "It is time to close the book on infectious diseases and declare the war against pestilence won." In truth, Stewart never claimed infectious diseases were "conquered". He was urging greater attention to chronic illnesses , a sensible priority at the time. But with AMR rising, perhaps the balance must shift again.
Antibiotic resistance is often described as an arms race . When a new antibiotic is deployed, disease rates initially drop , until bacteria evolve resistance. Old threats reappear, while our supply of new antibiotics dwindles .
Agriculture faces a similar battle. Overused pesticides and insecticides, even disease-resistant crop varieties, all lose their effectiveness as pathogens adapt . This leads to "boom and bust" cycles that force the creation of stronger chemicals or new crop varieties.
Researchers are exploring alternative strategies , including ways to harness natural epidemic fluctuations to push harmful species toward collapse . AMR researchers (including me) and agricultural scientists could learn a great deal from one another.
Beyond misuse: the environment's role
While the misuse and overuse of antibiotics remain major drivers of AMR, environmental factors - from wastewater discharge and pollution to pesticides, fertilisers, industrial proximity and climate - also play a role . The picture is complicated by differences in what is tested (river water, soil, air) and the type of contamination, such as wastewater and heavy metals. Drawing meaningful conclusions from such scattered evidence is daunting. The first step is to gather, organise and share it through a rigorous mapping process.
Our own evidence map revealed surprising gaps. Of the 738 studies reviewed, only 16 examined the atmospheric environment. Airborne microbes are harder to detect than those in water or soil, but the imbalance still raises questions. Most research focused on freshwater, probably because it is easier to access and more directly linked to human and agricultural use.
This prompts a provocative question: do scientists sometimes choose research topics not purely for their societal relevance, but because of logistical ease or publishing pressures that make "safe" studies more appealing than riskier or inconclusive ones?
Such decisions can skew research priorities toward what is convenient to study rather than what is most urgent, biasing the evidence base toward positive findings and leaving critical gaps - particularly in regions hardest hit by antibiotic resistance. For example, researchers might favour easily accessible freshwater sites over remote or politically unstable regions, even if the latter face greater threats, simply because fieldwork there is cheaper, safer, and more likely to produce publishable results.
Inequality in research
We also found a stark imbalance in where AMR research is led. The countries most vulnerable to resistance - low- and middle-income nations - accounted for only a small fraction of studies. Limited surveillance, less-regulated antibiotic use, higher disease burdens and poorer waste management all play a role.
Around 91% of research came from high-income countries, with nearly half led by scientists in China and the US. In recent years, China and India - the world's biggest antibiotic producers - have published far more AMR-related research than their research and development spending alone would predict. This suggests a strategic emphasis on AMR that goes beyond budget size, perhaps reflecting the countries' manufacturing dominance, national health priorities, and recognition that antibiotic resistance has direct economic and public health consequences at home.
Few studies have explored how climate change interacts with AMR, though this is now an accelerating field of inquiry. Recent evidence suggests the link is growing stronger. Similarly, until 2021, almost no research examined the role of microplastics in spreading resistance - but interest is now growing rapidly, with new studies investigating how these tiny plastic particles can act as surfaces for bacteria to exchange resistance genes and travel through water , soil and food chains.
Borges' library may, in theory, hold a perfect index to every meaningful book. But no one will ever find it. An evidence map is less romantic, but far more useful: it organises what we know, exposes the gaps, and highlights the patterns. In the fight against antibiotic resistance, it's a way to bring order to chaos, guiding the next chapters of research and policy.
Gianni Lo Iacono receives funding from from the European Union's Horizon 2020 Research and Innovation programme under grant agreement No 773830: One Health European Joint Programme (FED-AMR project) and the European Union's Horizon Europe Project 101136346 EUPAHW.
