Report finds positive associations between antimicrobial use in animals and AMR in humans

A new joint inter-agency report has found positive associations between antimicrobial use (AMU) in animals and antimicrobial resistance in animals as well as in humans.

The report, titled Antimicrobial consumption and resistance in bacteria from humans and animals, analysed possible relationships between antimicrobial consumption (AMC) in humans and food-producing animals, and the occurrence of antimicrobial resistance (AMR) in bacteria from humans and food-producing animals in the European Union (EU) / European Economic Area (EEA).

The report analysed data for six classes of antibiotics: Third and fourth generation cephalosporins, fluoroquinolones, polymyxins, aminopenicillins, macrolides and tetracyclines.

Except tetracyclines, all remaining five classes are critically important antimicrobials (CIA) categorised by the World Health Organization (WHO) as critical for use in human health.

Four out of these five CIAs are highest priority (HPCIA).  These classes are also included in the WHO AWaRe (Access, Watch, Reserve) classification.

The report analysed data from three years — 2016, 2017 and 2018 — for a comparison between antimicrobial consumption in food-producing animals and humans. Data from 2017 was used; for trend analyses data for 2014 and 2015 was included.

Analyses that involved AMR in bacterial isolates from animals included 2014 and 2015, as different animal species are monitored in even and odd years respectively.

Five different surveillance networks — coordinated by agencies covering EU member states, two EEA countries (Iceland and Norway) and Switzerland — contributed to data sets for the study.

The data used was collected as part of clinical and epidemiological surveillance / monitoring. Data on AMR in E. coli, K. pneumoniae, S. aureus and C. jejuni were included in this report: While E. coli and K. pneumonia are common infection causing pathogens, S. aureus and C. jejuni are food-borne bacteria.

According to the report:

Penicillins, first- and second-generation cephalosporins and macrolides were the highest selling classes in human medicine. For food-producing animals, tetracyclines and penicillins were the highest selling classes in 2017. The consumption of colistin, a last resort antibiotic and an HPCIA was higher in food-producing animals than in humans across EU.

The report also established significant correlations between AMU in humans and animals with AMR in humans, animals respectively and also across sectors. Antimicrobial use in food-animals is linked to AMR, not only in animals, but also in humans, according to the report.

For example, there was a significant positive association between consumption of fluoroquinolones and other quinolones in animals and resistance in E. coli from food-producing animals as well as humans. The consumption of third- and fourth-generation cephalosporins in food-producing animals was seen to be associated with resistance to third-generation cephalosporins in humans.

Although the resistance against colistin in isolates from food-producing animals was low, the consumption of colistin in animals had a significant impact on resistance to colistin in E. coli from food-producing animals.

Macrolide resistance in C. jejuni from humans was related to macrolide resistance in C. jejuni from poultry as well as turkey.

In food-producing animals, statistically significant positive associations between consumption of aminopenicillins and ampicillin resistance were found in E. coli across all years and for 2016 in Salmonella spp. from poultry.

Similarly, positive association between ampicillin resistance in E. coli from food-producing animals (turkeys, broilers, pigs and calves) and ampicillin resistance in invasive E. coli from humans was observed for all years, and between Salmonella spp. from turkeys and from humans in 2018.

The report suggested that strong interventions to reduce and improve antimicrobial consumption will have a beneficial impact on the occurrence of AMR. It underlined the need to promote prudent use of antimicrobial agents and infection control and prevention in both humans and in food-producing animals, in a ‘One Health’ approach.

Overuse and misuse of antimicrobials is one of the main drivers of antimicrobial resistance. As the global antimicrobial consumption in terrestrial and aquatic food animal production accelerates, which is linked with expanded production to meet increasing demand for animal-source nutrition, monitoring antimicrobial use becomes more and more relevant.

In resource constrained settings, where current surveillance systems for antimicrobial use are lacking, this can begin with CIAs or HPCIAs, given its relevance and need to preserve them for humans.

Appropriate data on the use of CIAs in humans and animals, and understanding on their linkages to AMR can help inform necessary policy decisions related to restricting the use of CIAs in animals or adoption of preventive measures to reduce dependence on antibiotics in food-animal production.

The report was published jointly by the European Centre for Disease Prevention and Control; the European Food Safety Authority; and the European Medicines Agency.

Subscribe to Daily Newsletter :

SUPPORT US

We are a voice to you; you have been a support to us. Together we build journalism that is independent, credible and fearless. You can further help us by making a donation. This will mean a lot for our ability to bring you news, perspectives and analysis from the ground so that we can make change together.