It kills millions every year, with a potential impact in the near future that could dwarf that of the Covid-19 pandemic but AMR, or antimicrobial resistance, remains a little-known problem outside specialist circles.

Experts say it is vital that we get a grip on it, with action needed across sectors from health to agriculture.

What is AMR?

Antimicrobial resistance (AMR) occurs when germs that cause sickness – bacteria, viruses, fungi and parasites – develop ways to resist the drugs traditionally used to treat them. The new, resistant pathogens are sometimes called “superbugs”.

How does it happen?

It is a natural process that happens over time, but is being accelerated by too much unnecessary use of medicines – particularly antibiotics – in humans, animals and plants. This is because exposure to the drugs helps the pathogens learn how to resist them.

How big a problem is it?

AMR is already a major problem. Bacteria resistant to antibiotics were directly responsible for 1.27 million global deaths in 2019, and thought to be a contributory factor in 4.95 million deaths.

It makes infections harder to treat, and makes other treatments riskier. Cancer patients, for example, are particularly vulnerable to infections because of the impact of their treatment on their immune systems. Likewise, organ transplant recipients who must take drugs to damp down their immune systems in order to prevent their bodies rejecting the new organs.

What about new drugs?

There is a severe lack of new antibiotics coming through the pipeline. A major barrier is the fact that, ideally, few doses of any new antibiotic will be used. Instead, they will be held in reserve to treat the worst infections that do not respond to any existing drugs.

Under traditional drug-pricing mechanisms, pharmaceutical companies are guaranteed little return on investment.

Many governments are trying out new ways to incentivise the development of novel antibiotics. In the UK, for example, NHS England essentially takes out a subscription to new antibiotics, guaranteeing pharmaceutical firms a steady income from the drugs whether or not they are used.

There are also questions around whether we are using existing treatments effectively. In some countries, people struggle to get access to what the World Health Organization calls “access antibiotics” – older types in pill form that generally have fewer side effects and less likelihood of driving AMR. In those countries, people who have money may be instead offered injectable, newer antibiotics that are actually more likely to drive resistance.

What needs to change?

Tackling this problem needs a “one health” approach, experts say, recognising the interdependence of human health with the health of animals, plants and ecosystems.

Farmers need to use antibiotics on their plants and animals only when needed, doctors must not prescribe antibiotics for infections caused by viruses, and pharmaceutical companies must manage the waste created during manufacture to stop antibiotics finding their way into the environment.

Much of this is likely to need formal government policies, although a report earlier this year by the Global Coalition on Aging into 11 countries’ efforts warned that despite some progress, “stagnancy” was creeping into programmes.

What can individual patients do?

Stopping infections in the first place by simple hygiene measures such as handwashing can make a difference. And when prescribed antibiotics, the official advice is to take them exactly as prescribed and not save them for later or share them with others.