What is antimicrobial resistance – and why is it a global health threat?

Microbes are tiny organisms that are largely invisible to the naked eye. Bacteria, fungi and viruses are all types of microbes. Most are harmless. Some, however, can cause infections that make us ill.

A lot of infections are self-limiting, meaning our bodies can overcome them on their own. But sometimes we need help, especially if our immune system isn’t strong enough. This is more often the case in elderly people, newborn babies or people who are already sick.

In these instances, the infection will often be treated with a drug designed to kill the microbe: an antimicrobial. For a fungal infection, it’s an antifungal. For a viral infection, it’s an antiviral. And for a bacterial infection, it’s an antibiotic.

Where does antimicrobial resistance come into it?

Drugs are never guaranteed to work. Microbes are adaptable and can learn ways to defend themselves against antimicrobials. And once they’ve done so, they multiply. This means the drugs that worked last time won’t work next time. This is known as antimicrobial resistance (AMR).

The result is that illnesses such as typhoid, gonorrhoea and tuberculosis – all caused by microbes – are becoming harder to treat. And as more bacteria become resistant to antibiotics, routine medical procedures that rely on them to prevent infection could become life-threatening. These include Caesarean sections, chemotherapy, organ transplants and joint replacements.

Some microbes have developed resistance to multiple drugs. These are known as “superbugs”. Doctors treating patients with these infections can have no choice but to use extremely strong antibiotics – often those that are meant to be reserved as a last resort. If these fail, the infection can be fatal.

More and more infections are responding only to the strongest antibiotics. As microbes become increasingly exposed to these drugs, they are developing resistance to treatments that often represent the last chance of survival.

What’s behind the problem?

Antimicrobials, particularly antibiotics, are often overused and poorly managed around the world. Human use of antibiotics rose by almost half between 2000 and 2018 alone. This makes the emergence of superbugs more likely.

Industrial farming practices are also intensifying the issue. Cramped and dirty conditions on factory farms allow disease to flourish, and farmers can become reliant on drugs to keep animals healthy. Farm animals are also often given antibiotics to encourage growth (a practice banned in the EU). The meat industry is responsible for 73% of global antibiotic use. All this has the same effect as it does in humans: of fostering drug-resistant infections.

Antibiotic use on farms also creates a problem for humans, because we eat meat from these animals. And if bacteria from undercooked meat gives you an infection – like salmonella or E.coli – it’s increasingly likely to be able to defend itself against the drugs your doctor gives you.

How big is the issue?

Huge. Drug-resistant infections are a leading killer worldwide, claiming almost 5 million lives a year, according to the most recent figures. That’s more than the lives lost to HIV and malaria combined.

And it’s the poorest and most vulnerable people who face the greatest risk. Infections are more likely to occur in places with looser drug regulations, poor access to vaccines or a scarcity of clean water and sanitation. Over 99% of children under five known to have died from a drug-resistant infection have been in low- and middle-income countries (LMICs).

The threat, however, is global: it’s estimated that by 2050, as many as 10 million people a year could die because the drugs we rely on to treat illnesses are no longer working.

Can’t we just make new antibiotics?

It can take 10 to 15 years and more than $1bn to develop a new antibiotic. The last antibiotic that successfully made its way onto the market was discovered in 1987.

This is mostly because the science behind developing these drugs is extremely complicated. The drug needs to be able to kill the specific microbe causing the disease without harming the patient. Antimicrobial drugs carry the added risk of becoming redundant if the bacteria they’re targeting develop resistance.

The upshot is that pharmaceutical companies are less inclined to invest in antibiotic development. Many have pulled out of it altogether.

So, how do we solve the problem?

One way is by stopping infections in the first place. A recent report estimated that about 750,000 deaths a year linked to antimicrobial resistance in LMICs could be prevented through measures that achieve this, such as access to clean water, sanitation, hygiene and vaccinations.

When infections do occur, doctors need access to the right diagnostic tools. The quicker you identify the infection and its causes, the quicker it can be treated and stopped from spreading.

In many countries, the resources needed to perform these diagnostic tests are lacking and doctors are forced to take a shot in the dark with the drugs they use. Prescribing the wrong antibiotic loses precious time to treat the patient.

On top of that, the right drugs need to be available at the right time and place. And we need to regulate the use of antimicrobials in both animals and humans, so that they are only prescribed when necessary and with proper testing.

Global action is required – action that ensures equitable access to life-saving drugs while managing how they are used around the world.