Research and analysis

Executive summary Third UK One Health Report

Published 29 November 2023

1. Antibiotic consumption

Antibiotic use (AMU) is the major driver of antimicrobial resistance (AMR). In 2019, a total of 706 tonnes of antibiotics were consumed in the UK, of which people consumed 68% (478 tonnes) and animals consumed 32% (228 tonnes). Between 2014 and 2019, the total quantity of antibiotics consumed in humans and animal in the UK has decreased by 28%.

Infographic showing overall tonnes of antibiotic used in 2014 was 989 tonnes and decrease by 28% to 706 by 2019. This is a 51% and 13% decrease in animals and human respectively.

Between 2014 and 2019, consumption when adjusted for underlying population, decreased in food-producing animals by 52% (from 62 mg/kg to 30 mg/kg) and in humans by 18% (from 125 mg/kg to 103 mg/kg).

Infographic showing antibiotic active ingredient adjusted for underlying population (mg/kg) in food producing animals and humans in 2014 and 2019.

• In 2014, 62 mg/kg of antibiotic were consumed by food-producing animals and 125 mg/kg were consumed by humans.
• In 2019, 30 mg/kg of antibiotics were consumed by food-producing animals and 103 mg/kg we consumed by humans.
• Food-producing animals saw a 52% decrease in antibiotic consumption between 2014 and 2019, whereas, human saw an 18% decrease.

Certain antibiotics used in human and veterinary medicine are classed as highest-priority, critically important antibiotics for use in people (HP-CIAs). A key focus of the animal sector’s stewardship initiatives has been to minimise use of HP-CIAs, to help ensure they continue to be effective in people for as long as possible. Between 2014 and 2019, consumption of HP-CIAs in animals decreased by 75% to a very low level (0.17 mg/kg).

2. Antibiotic resistance

Antimicrobial resistance (AMR) refers to the ability of any microbes (bacteria, as well as viruses, fungi, and protozoa) to resist treatment to drugs designed to kill them or stop their growth. This report focuses on resistance in key bacteria.

2.1 Salmonella spp.

AMR in Salmonella spp. varies widely across the animal and human sectors. This is due to the differing patterns of AMR between individual Salmonella serovars circulating in humans and animals. For the majority of antibiotics tested, resistance is higher in human patients than in chickens, although is mostly declining in both species. One exception to this is resistance to the HP-CIAs third- and fourth-generation cephalosporins and quinolones, which is higher in people and appears stable.

2.2 Campylobacter spp.

Similar patterns of AMR in Campylobacter spp. are reported across chickens, chicken meat, and human patients, suggesting strong linkages through the food chain. High levels of fluoroquinolone resistance (>40%) have persisted across the sectors despite very low usage of these antibiotics in chickens.

Graph showing percentage resistance to ciprofloxacin in Campylobacter jejuni from humans, chickens and retail chickens.

• In humans, resistance to ciprofloxacin was 44% in 2014, 44.9% in 2015, 44.8% in 2016, 45.8% in 2017, 46.8% in 2018 and 47.1% in 2019.
• In chickens, resistance to ciprofloxacin was 43.6% in 2014, 40.6% in 2016 and 48% in 2018.
• In retail chicken resistance to ciprofloxacin was 49.1% in 2014/2015, 54.2% in 2015/2016, 41.1% in 2016/2017, 52.1% in 2017/2018 and 51% in 2018/2019.

2.3 Escherichia coli

Large declines in resistance to most antibiotics have been observed in E. coli from chickens, and to a lesser extent, pigs, whereas resistance in human patients has remained stable or declined slightly over time. Resistance to the HP-CIAs, third- and fourth-generation cephalosporins, is considerably higher in human patients than in animals, and appears to be increasing.

Graph showing percentage resistance of third- and fourth-generation cephalosporins in E. coli from chickens, pigs and humans.

• In chickens, resistance was 0% in 2014, 0% in 2016 and 1.6% in 2018.
• In pigs, resistance was 0% in 2015, 0% in 2017 and 1.4% in 2019.
• In humans, resistance was 10.8% in 2015, 11.2% in 2016, 12.6% in 2017, 13.4% in in 2018 and 13.9% in 2019.

2.4 Extended spectrum beta-lactamases (ESBL) and AmpC- producing E. coli

We also perform more sensitive type of testing in animals and food using selective media. This test inhibits the growth of susceptible bacteria but allows ESBL/AmpC-producing E. coli to multiply, making them easier to detect. There have been substantial reductions in the proportion of chickens carrying ESBL- and AmpC-producing E. coli, and a similar reduction in the presence of these bacteria in chicken meat. These organisms are resistant to the HP-CIAs, third- and fourth-generation cephalosporins, and the decline in carriage is most likely due to reduced use of antibiotics in the meat poultry sector. By contrast, the presence of ESBL- and AmpC- producing E. coli in pigs has reduced slightly over time. Levels in pork meat are much lower than in pigs, which reflects the effectiveness of slaughterhouse processes in clearing bacteria for these animals.

Graph showing ESBL-producing E. coli isolated from chickens, pigs, retail chickens and pork.

• In chickens, detection was 19.1% in 2016 and 4% in 2018.
• In pigs, detection was 15.0% in 2017 and 15.3% in 2019.
• In retail chicken, detection was 29.7% in 2016 and 8.4% in 2018.
• IN pork, detection was 1.6% in 2015, 0% in 2017 and 0.7% in 2019.

2.5 Summary

The trend of AMR in Salmonella and E. coli carried by pigs and chickens differ from those in human patients. By contrast, resistance in Campylobacter from chickens, chicken meat, and human patients is much more similar, due to foodborne transmission of these bacteria.

3. The natural environment: an emerging area

AMR exists in natural environments (e.g., air, water, soil). The spread and impact of AMR in the environment between and among humans and animals is poorly understood. There is no established ongoing surveillance programme for AMR in the environment in the UK, however, this is an area under active development, including in the PATH-SAFE programme.

4. Companion animals: an emerging area

Companion animals refers to animal species kept as pets. Sales data on veterinary antibiotics licensed for use in companion animals are routinely collected, however, there is no system to monitor the prevalence of AMR in UK pets. Due to the close contact between companion animals and humans there is considerable potential for transfer of AMR.

4.1 Antibiotic consumption in dogs and cats in the UK

In dogs and cats, antibiotic sales data indicates that between 2014 and 2019, both overall use and the use of HP-CIAs decreased. However, the use of HP-CIAs is still high, particularly in cats.

4.2 Antibiotic resistance in companion animals

New research on AMR in companion animals showed that dogs fed raw diets were significantly more likely to excrete ESBL-producing and multi-drug resistant (MDR) E. coli in their faeces than dogs fed non-raw diets.

4.3 Antibiotic resistance in companion animals

New research on AMR in companion animals showed that dogs fed raw diets were significantly more likely to excrete ESBL-producing and multi-drug resistant (MDR) E. coli in their faeces than dogs fed non-raw diets.

Infographic showing potential transmission pathways of AMR via raw pet food.

• Raw meat and offal, which harbours bacteria, is manufactured into raw pet food (RPF).
• 39% of RPF samples contained E. coli resistant to at least one antibiotic.
• Dogs fed raw meat diets are almost 3 time as likely to be shedding resistant E. coli as dogs fed non-raw diets.
• Bacteria, including resistant bacteria, can get on to owners’ hands, the food bowl, any utensils used for food preparation, the food preparation surface, etc.
• Dogs can pick up bacteria from their food, which can be transmitted to owners.
• Not washing hands properly can lead to spread.
• Bacteria, including resistant bacteria, are excreted in dog faeces.
• Bacteria, including resistant bacteria, can spread from Faeces direct to people, or into the environment.

5. Control measures and new initiatives

Infographic showing ongoing UK initiatives in antibiotic stewardship and AMR surveillance described in the report and the year they were initiated.

5.1 Initiatives in 2014

• Antibiotic Guardian, antibiotic stewardship programme
• Harmonised monitoring, surveillance initiative

5.2 Initiatives in 2015

• ResAlert, surveillance initiative

5.3 Initiatives in 2016

• Responsible Use of Medicine in Agriculture (RUMA) Alliance Targets, antibiotic stewardship programme
• eBug programme, antibiotic stewardship programme

5.4 Initiatives in 2017

• Treat Antibiotics Responsibly Guidance Education Tools (TARGET), antibiotic stewardship programme

5.5 Initiatives in 2020

• Private Laboratory Initiative, surveillance initiative

5.6 Initiatives in 2021

• Arwain Vet Cymru, antibiotic stewardship programme
• Farm Vet Champions, antibiotic stewardship programme
• Medicine Hub, antibiotic stewardship programme
• PATH-SAFE programme, surveillance initiative
• VetTeam AMR, antibiotic stewardship programme
• Welsh Lamb and Beef Producers AMU calculator, antibiotic stewardship programme
• One Health Integrated Surveillance sub-group of Defra Antimicrobial Resistance Coordination Group, surveillance initiative
• Antibiotic Amnesty, antibiotic stewardship programme