Antimicrobial resistance

Antimicrobial resistance (AMR) happens when antimicrobial medicines are no longer effective in killing or slowing the growth of microorganisms that cause disease. This makes infections harder to treat and increases the risk that diseases will spread.

Antimicrobial medicines include antibiotics, antivirals, antifungals and antiparasitics. AMR affects all four categories of antimicrobials.

Bacteria, viruses, fungi or parasites that have developed this kind of resistance are sometimes called ‘superbugs’. Strains of bacteria that have developed resistance to antibiotics include methicillin-resistant Staphylococcus aureus (MRSA) and Clostridioides difficile (C diff).

AMR has been described as a ‘catastrophic threat’ to human and animal health. Bacterial AMR was linked to an estimated 4.95 million deaths and was directly responsible for 1.27 million deaths worldwide in 2019. Researchers have estimated that this figure could increase to 1.91 million by 2050.

What causes AMR?

The development and spread of AMR are accelerated by the inappropriate use of medicines (for example, prescribing antibiotics to treat a viral infection), use of low-quality medicines and poor infection control. The widespread use of antimicrobials in agriculture also has an effect. Accumulating evidence suggests that resistance that develops in farmed animals or in the natural environment can spread to humans.

Why is AMR a problem?

AMR reduces our ability to treat infectious diseases, resulting in prolonged illnesses, more complications and disability, and an increased risk of disease spread. AMR also compromises advances in modern medicine that rely on effective antimicrobials, such as organ transplantation, chemotherapy, and major surgery.

AMR also affects animal health and the wider environment, and has implications for food security, environmental wellbeing and socio-economic development. In March 2017, the World Bank Group estimated that the effects of AMR could reduce annual global gross domestic product by between 1.1% and 3.8% by 2050.

What is the UK doing to address AMR?

UK policy on AMR is informed by a ‘one health’ approach, which recognises the interconnectedness of human, animal and environmental health. There are three key aspects to AMR policy: reducing rates of infection (and hence the need to use antimicrobial medicines), ensuring that antimicrobials are used appropriately when they are needed, and supporting the development and supply of new diagnostic tools, vaccines and treatments.

The UK-wide 20-year vision for antimicrobial resistance sets out the government’s plans to contain and control AMR by 2040. This document is backed up by the five-year national action plan, Confronting antimicrobial resistance 2024 to 2029, setting out commitments and targets to reduce the inappropriate use of antimicrobials and numbers of drug-resistant infections. The UK plan is informed by the World Health Organization’s global action plan on AMR.

The 2024 to 2029 national action plan sets out specific targets, including:

• preventing an increase in the numbers of certain drug-resistant infections in humans (compared with a 2019-20 financial year baseline)
• increasing UK public and healthcare professionals’ knowledge on AMR by 10% (compared with 2018 and 2019 baselines respectively)
• reducing total antibiotic use in humans by 5% (compared with 2019).

Is UK action to address AMR working?

In March 2024, the then government said that the majority of commitments in the previous 2019 to 2024 national action plan were assessed as completed or on track for delivery. These included targets to reduce numbers of drug-resistant infections and limit the use of antibiotics in humans and animals.

Targets to reduce sales of antibiotics for use in food-producing animals have been met. Sales fell 57% between 2014 and 2024.

Less progress has been made on reducing the use of antibiotics and the numbers of drug-resistant infections in humans, which are increasing.

Data from England shows that the use of antibiotics in humans fell by just 2% between 2019 and 2024, against a target of 15% by 2024. This target has now been revised down, with the 2024 to 2029 national action plan setting a new aim to reduce antibiotic use in humans by 5% compared with a 2019 pre-pandemic baseline. In addition, drug-resistant infections increased by 13.1% between 2019 and 2024, with most of this increase seen in the last two years.

In February 2025, the National Audit Office (NAO) published a report on the government’s work to address AMR. It reported that the government spent £567 million on AMR programmes between 2020-21 and 2023-24. The NAO report highlighted some achievements, but found that limited progress had been made towards targets set in the 2019 to 2024 action plan. It said that the “less stretching” targets in the 2024 to 2029 plan may be more achievable, but may not deliver progress towards achieving the goals set out in the 20-year vision for AMR.

In response to the NAO report, the Public Accounts Committee made a series of recommendations, including that the government should regularly review and publish updates on its progress against AMR targets and address shortcomings in data collection, sharing and analysis. The committee said that AMR should be considered in UK trade deals with other countries, that the management of wastewater should be treated as a public health concern, and that better use should be made of diagnostic tests. The government responded in August 2025 and agreed with the committee’s recommendations.

Further reading

• Commons Library briefing The use of antibiotics on healthy farm animals and antimicrobial resistance
• Lords Library briefing Antimicrobial Resistance: Global Policy Initiatives
• POSTNote Reservoirs of Antimicrobial Resistance
• POSTNote Antimicrobial Resistance and Immunisation
• POSTNote Antibiotic Resistance in the Environment