What I've learnt from a decade of campaigning on superbugs – Dame Sally Davies

This article has been updated.

In 1928, Alexander Fleming discovered the first antibiotic, penicillin, and by the 1930s, the first antibiotics had become commercially available.

Now, less than a century later, we are facing a health crisis as many drugs that have commonly been used are no longer effective and we struggle to find new treatments to combat infections.

So-called 'superbugs' which have become resistant to the medicines once used to treat them kill an estimated 5 million people a year. This antimicrobial resistance (AMR) has been described as “one of the biggest threats to global health, food security and development today”.

"Antibiotics underpin modern medicine," says the UK government's special envoy on antimicrobial resistance, Dame Sally Davies.

"I can't conceive of cancer care effectively without antibiotics, let alone many operations, including caesarean sections, transplants, or diabetic care. All of these need antibiotics because people are prone to life-threatening infections."

Davies has been advocating for a united approach to tackling AMR for over a decade, including making systemic changes and rethinking how we use antibiotics in humans and animals, as well as supporting and incentivizing the discovery of new drugs.

Without urgent action, she says, we risk a return to the pre-penicillin time when common infections were life-threatening, setting back decades of medical progress.

AMR occurs when microbes – bacteria, fungi, parasites and viruses – evolve to the point where antimicrobial drugs that previously worked against them are no longer effective. As a result of this drug resistance, infections spread and become harder to treat.

Some strains of bacteria have become “superbugs”, developing resistance to multiple forms of treatment. These include MRSA (methicillin-resistant Staphylococcus aureus), Clostridium difficile (C. diff) and the bacteria that cause multi-drug-resistant tuberculosis.

AMR affects all countries, although some are feeling the impact more than others. In particular, Sub-Saharan Africa may bear a particularly heavy burden. However, there is currently a lack of high-quality data on AMR and infectious diseases in low-income areas, researchers say.

We urgently need more innovative, high-quality antimicrobials as resistance spreads and drugs such as antibiotics become less effective.

AMR directly caused 1.27 million deaths globally in 2019 and contributed to an additional 4.95 million deaths. This makes it a bigger killer than HIV/AIDS or malaria. Forecasts suggest that by 2050 AMR-related deaths will be 70% higher than they were in 2022. Improving access to healthcare and effective antibiotics could save 92 million lives between 2025 and 2050.

The impacts aren’t limited to health alone. The global economy will also be affected by higher healthcare costs, reduced productivity and an increase in poverty as a result of antimicrobial resistance. Without action, it could reduce global GDP by $3.4 trillion and drive an additional 24 million people into extreme poverty, the United Nations (UN) warns.

Natural variations in the genetic makeup of microbes cause resistance to develop over time as they reproduce. For example, alterations in their DNA could mean antimicrobials can no longer reach the microbe cell or make microbes capable of creating enzymes that destroy the antimicrobial. Through natural selection, these microbes with advantageous traits will proliferate over less-resistant strains, spreading the genetic advantage more widely.

Microbes, like bacteria, are also able to directly transfer genetic material to each other in various ways other than reproduction.

Although both of these ways of transferring genetic material occur naturally, poor use of antimicrobials, among other things, can speed up resistance development and spread. For example, if an antibiotic course does not completely kill off an infection, we leave behind the microbes best able to fight against the drug. These will then multiply and pass on their survival traits.

Excessive antibiotic use is a significant driver of resistance. If the treatment is too short, weak, or incorrect for the infection, we risk leaving behind resistant microbes. The more we expose microbes to antimicrobials and/or other resistant microbes, the more opportunities we create for resistance to develop and multiply.

And it’s not just prescribing to humans that is a problem – two-thirds of antibiotics globally are used in farming. In recent years, antibiotic use in agriculture in Europe has fallen dramatically. But they continue to be widely used in emerging economies because of their impact on profit margins and a lack of viable and affordable alternatives.

"We've got to use the treatments, the antibiotics, the antivirals, antifungals carefully, only use them when we need them," Davies explains, "but we also need to use them carefully in animals. If the animals are sick, of course they need treating. But actually, if it's just because it's cheaper than infection prevention and control then that is not acceptable."

The environment and climate change also have a role to play in the emergence, transmission and spread of antimicrobial resistance, as a recent report from the UN points out. Pollution from healthcare, pharmaceuticals, food and agriculture – such as wastewater from hospitals or agricultural runoff – is particularly problematic, as it may contain both antimicrobials and resistant organisms.

Introducing these to the broader environment will also impact biodiversity and soil health.

Indeed, research published in The Lancet points to a link between AMR and air pollution. Researchers studied the possible impact of air pollution (PM2.5) on antibiotic resistance in 166 countries, and those with higher levels of air pollution were also found to have higher levels of AMR.

Poor sanitation and access to clean water is another major contributory factor. In countries that lack these basic hygiene measures, water is the primary vector by which antimicrobial resistance and its associated diseases are spread. Improved sanitation, water treatment and basic hand-washing and hygiene facilities are crucial steps in curbing the spread of AMR, as the World Economic Forum points out in a briefing paper.

Global coordination is needed to tackle the rise of antimicrobial resistance as well as foster the development of new drugs. We must also work together to ensure healthcare systems worldwide are prepared for rising resistance and infection levels.

This involves taking a 'one health' approach to combat AMR, which recognizes the connection between people, animals, plants and the environment they share.

For example, during the World Economic Forum's 2025 annual meeting in Davos the Forum’s Global Future Council on Tackling Antimicrobial Resistance developed and released the Davos Compact on AMR.

This compact outlines how the public and private sectors can engage and highlights the key areas of focus to tackle AMR. This will inform the work of the Unified Coalition for the AMR Response (UCARE), a collaboration between governments, philanthropic organizations and the private sector, which was launched by the Forum’s Centre for Health & Healthcare in Davos in January 2025.

UCARE is focused on:

Given the length of time it could take to develop new treatments, Davies echoes the need to focus on these areas.

"I'm calling on leaders to fund the research, to find new treatments and new vaccines and prevention," she says.

"Studies show the payback is massive, that it pays off over 10 to 30 years, 10 times. So make that investment, save lives, save your economies, save the food chain."