Europe establishes a unique link between veterinary antibiotics
and resistance in humans
However, in France, large animal vets prescribe fewer antibiotics than doctors:
99 mg/kg in production animals compared to 176 mg/kg in human medicine – the
European record.
Comparison of antibiotic use in humans and animals, in mg/kg (data 2012)
In most countries, exposure to antibiotics is lower in animals than in humans, except in seven high-consuming
European countries (in particular southern Europe and Germany).
‘These results should be interpreted with caution’. This warning is repeated twenty times
throughout the 114 pages of the report on antibiotic use and antibiotic resistance, produced
jointly by the three European health agencies, the European medicines agency (EMA), the
European food safety authority (EFSA) and the European centre for disease control (ECDC).
On 30 January, the agencies published a joint report for the first time on the impact of
antibiotic use in animals on the level of antibiotic resistance in man (on the basis of sales
figures and levels of resistance for 2012).
Comparison in volumes of antibiotics used in Europe in man or in animals does not really
give a negative image of veterinarians. True, in volume, vets of the 26 European countries
included in the report prescribed a total of 8,000 tonnes of antibiotics in 2012 for production
animals, more than double that of doctors (3,400 tonnes). However, this analysis is
meaningless without taking into account the biomass of the two billion production animals: 55
million tons of live weight. In comparison, the 507 million inhabitants of the 26 countries
represent a biomass of 29 million tonnes with an average bodyweight of 62.5 kg per person.
This takes into account the average adult bodyweight (70 kg) and the lighter bodyweight of
children.
116 mg/kg in humans, 144 mg/kg in animals
In relation to the biomass, antibiotic consumption in Europe is 144 mg/kg in animals,
compared to 116 mg/kg in humans. In France, veterinarians have no reason to be ashamed;
they prescribed 99 mg/kg antibiotics in production animals. On the other hand, French doctors
merit the European gold medal of antibiotic prescription, with 176 mg/kg.
In most European countries (18 of 26), antibiotic use in animals is lower than that in humans.
However, the high antibiotic use in animals in the remaining seven European countries –
southern Europe, Germany, Poland and Belgium – makes that on average, animals are more
exposed than humans (+24%).
15 times more 3GC/4GC in humans than in animals
In all European countries, doctors are much greater prescribers of critical antibiotics – third
and fourth-generation cephalosporins (3GC/4GC) and fluoroquinolones – than veterinarians.
Doctors still prefer broad-spectrum beta-lactams. Prescriptions for 3GC/4GC are fifteen times
higher in humans (3.5 mg/kg) than in production animals (0.24 mg/kg). Those for
fluoroquinolones are nearly three times higher in humans (7.04 mg/kg) than in animals
(2.47 mg/kg).
A unique link between antibiotics and resistance in animals
At European level, all studied correlations were positive and significant between sales of
veterinary antibiotics and the level of resistant indicator or zoonotic germs in animals (cattle,
pigs, poultry): E. coli, Salmonella and Campylobacter (see Table). In animals, these
pathogens are isolated from healthy individuals as part of resistance monitoring programmes.
Samples are usually taken at the slaughterhouse.
However, the report lists many precautions in the interpretation of these results. Resistance
rates observed in 2012 stem from the selection pressure of use during the previous years or
even decades. But the statistical analysis only looks at the consumption in 2012. Furthermore,
the correlation does not take into account the distribution of antibiotic use according to animal
species, route of administration, dosages, indications, resistance mechanisms (mutation or
spread of plasmids), co-resistance or movement of animals between countries, promoting the
spread of resistance to countries with low antibiotic use.
Veterinary use also has an impact on E. coli in humans
Unlike in animals, the correlations between sales of human antibiotics and the resistance level
of these same pathogens (E. coli, Salmonella and Campylobacter) isolated from clinical cases
in humans are not all positive and significant. The correlation is well observed with the
resistance of E. coli. But it is not observed in human clinical cases of Salmonella or
Campylobacter of probable animal origin (zoonotic infections). This suggests that it is not the
selection pressure of antibiotics prescribed for humans that is at the source of this resistance.
The correlation between veterinary antibiotic use and resistance in humans is the most
original and unexpected point of this report. Because it clearly suggests that veterinary use has
a significant impact on the resistance observed in human medicine. This correlation is mainly
observed in Enterobacteriaceae: E. coli and Salmonella. But for the coliform bacteria, the
report notes that the part of their resistance to antibiotics that can be attributed to the use of
the antibiotics in man is larger than of the same compounds in animals.
Correlations between antibiotics and resistance for E. coli, Salmonella and Campylobacter.
Antibiotic sales
Level of resistance of E. coli, Salmonella and Campylobacter
Positive and significant link
No or weak link with resistance
between antibiotic use and
(not significant)
Correlations
resistance
Veterinary antibiotics
Pathogens of animal origin
Third and fourth generation
cephalosporins
E. coli and Salmonella
Fluoroquinolones
E. coli, Salmonella and
Campylobacter
Macrolides
Campylobacter
Tetracyclines
E. coli, Salmonella and
Campylobacter
Human antibiotics
Third and fourth generation
cephalosporins
Fluoroquinolones
Pathogens of human origin
E. coli
Salmonella
E. coli (and C. jejuni)
Salmonella and Campylobacter
Macrolides
Campylobacter
Tetracyclines
Salmonella and Campylobacter
Veterinary antibiotics
Third and fourth generation
cephalosporins
Fluoroquinolones
Tetracyclines
Pathogens of human origin
E. coli and Salmonella
E. coli
Salmonella and Campylobacter
Salmonella
S. Enteritidis
Source:
ECDC/EFSA/EMA first joint report on the integrated analysis of the consumption of antimicrobial
agents and occurrence of antimicrobial resistance in bacteria from humans and food-producing
animals
http://www.ema.europa.eu/docs/en_GB/document_library/Report/2015/01/WC500181485.pdf
30 January 2015.