A Problem Hidden in Plain Sight
Every year, infections that were once straightforward to treat become harder — or in some cases, impossible — to cure. The reason is antimicrobial resistance (AMR): the process by which bacteria, viruses, fungi, and parasites evolve to survive the drugs designed to kill them.
AMR is frequently described by public health bodies as one of the most significant long-term threats to global health. Unlike an acute epidemic, it develops gradually and mostly invisibly — which makes it easy to deprioritise until a crisis point is reached.
How Does Resistance Develop?
The core mechanism is evolutionary. When a population of bacteria is exposed to an antibiotic, most die — but any that carry a random genetic mutation conferring resistance survive. They then reproduce, passing that resistance on. Over time, the resistant strain can come to dominate.
Several human behaviours dramatically accelerate this process:
- Overprescribing: Antibiotics given for viral infections (where they have no effect) still kill beneficial bacteria and select for resistant strains.
- Incomplete courses: Stopping a course of antibiotics early can leave partially resistant bacteria alive to multiply.
- Agricultural use: Antibiotics are widely used in livestock farming — both therapeutically and historically as growth promoters. This creates large reservoirs of resistant bacteria that can transfer to humans.
- Poor sanitation: In settings where hygiene infrastructure is inadequate, resistant strains spread more easily between individuals.
What Types of Infections Are Affected?
Resistance has emerged across a wide range of pathogens:
- MRSA (methicillin-resistant Staphylococcus aureus) — a well-known hospital-acquired infection resistant to many common antibiotics.
- Drug-resistant tuberculosis — TB strains that do not respond to first- or second-line treatments, requiring longer and more toxic therapies.
- Carbapenem-resistant enterobacteria — resistant to one of the last-resort antibiotic classes, making infections extremely difficult to manage.
- Drug-resistant gonorrhoea — an increasingly prevalent STI that is becoming harder to treat effectively.
The Consequences for Modern Medicine
Much of modern medicine depends on antibiotics working. Routine surgeries — hip replacements, caesarean sections, organ transplants — carry an elevated infection risk. If those infections cannot be controlled with antibiotics, what is currently a manageable complication becomes potentially life-threatening.
Chemotherapy suppresses the immune system; patients rely on prophylactic antibiotics to prevent opportunistic infections. The same is true for premature newborns and patients in intensive care.
What Is Being Done About It?
International Coordination
The World Health Organization has designated AMR a global health priority and published a list of pathogens for which new treatments are most urgently needed. International agreements increasingly include commitments to reduce unnecessary antibiotic use.
New Drug Development
The antibiotic pipeline has been thin for decades — it is not commercially attractive for pharmaceutical companies to invest heavily in drugs that should ideally be used sparingly. Various push-and-pull incentive mechanisms, including guaranteed purchase commitments, are being trialled to encourage development.
Stewardship Programmes
Hospitals and healthcare systems are implementing antibiotic stewardship programmes — systematic approaches to ensure antibiotics are prescribed only when necessary, in the right dose, for the right duration.
What You Can Do
- Take antibiotics only when prescribed by a healthcare provider.
- Always complete the full prescribed course.
- Never share antibiotics or use leftover prescriptions.
- Practise good hygiene to prevent infections in the first place.
AMR is not inevitable. It is a consequence of choices — individual and collective. The sooner those choices change, the more medicine we preserve for future generations.