Europe is worried about the resistance in cats, dogs and horses
towards their owners
Since they are colonised by commensal and opportunist resistance germs, dogs,
cats and horses should be considered as an animal reservoir of resistance genes
for their owners. For veterinary surgeons they even pose a professional health
risk, according to the European Medicines Agency.
Owners of companion animals expose themselves to the risk of acquiring antimicrobial
resistance from their dogs, cats and horses through petting and handling on a daily basis. And
the pets are just as exposed to a transfer of resistance from their owners. The European
Medicines Agency points out the zoonotic risk of methicillin-resistant Staphylococci (MRSA
and MRSP), or of the extended-spectrum beta-lactamases (ESBL) resistance to last generation
cephalosporins…
The topic of the reflection paper on the risk of antimicrobial resistance transfer from
companion animals (horses included) to humans is more worrying than reassuring for their
owners and vets. Yet the zoonotic risk through simple contact has been much less studied than
the transmission of resistance of animal origin through the food chain.
Companion animal number is on the increase, as are the close and frequent contacts with their
owners. Growing medicalization has lead to an increase in antimicrobial treatments of these
animals, often without prior susceptibility testing and based on beta-lactams – like in human
medicine.
Companion animals could therefore represent an animal reservoir of resistance for all incontact humans. And vice versa, companion animals can also be colonised by resistant germs
from their owners. Finally, problems linked to resistant nosocomial infections in veterinary
clinics are similar to those in human hospitals.
Experts of the European medicines agency evaluated this transfer for methicillin resistant
staphylococci (S. aureus for the “human” MRSA and S. pseudintermedius for the MRSP in
dogs), ESBL-producing bacteria and vancomycin resistant enterococci (VRE).
Regarding MRSA, this is usually considered to be a human-to-animal transmission (dogs in
particular) than the other way around. But MRSP infections, common in dogs and cats, may
also constitute an animal reservoir of resistant genes that can be spread to MRSA in people.
Outranking the MRSA, the extended-spectrum beta-lactam (ESBL) and carbapenem
resistances have become the main concern for human medicine. These genes with a resistance
to third and fourth generation cephalosporin and to carbapenems spread rapidly between
bacterial species (enterococci and other Gram-negative bacteria) and between animal species,
through direct or indirect contact. Since the launch of cefovecin (Convenia®) in 2006, the
paper notes an increase of 3-5% of ESBL-producing E. coli in dogs and cats. These
resistances, although still rare, are the most alarming due to their rapid spread. The EMA
describes it as a “worldwide pandemic” in humans.
Vancomycin resistant enterococci (VRE) are the source of nosocomial infections in humans.
Dogs and cats could act as reservoir, transferring VRE to their owners. However, no canine
VRE has been isolated recently. Nevertheless, the EMA recommends monitoring this
bacterium in view of its ampicillin resistance which seems to precede vancomycin resistance
by a few years. However, no glycopeptide has been used in animals in the past 25 years.
The Agency issued four recommendations.
1. Fist, the impact of antimicrobial resistance on public health should be taken into
account in the applications of new compounds or new indications for existing
compounds for companion animals, as is already the case in food-producing animals.
Such a risk assessment would allow establishing new precautions in the SPC to limit
the impact of the transfer of resistance of treated animals.
2. End 2014, the EMA will propose risk mitigation options for critically important
antimicrobials for human medicine, including for companion animals and horses.
3. The Agency proposes to monitor the cascade use of human-authorised antibiotics in
companion animals.
4. Finally, the EMA recommends extending AMR surveillance programmes to
companion animals, no doubt to include monitoring of MRSP and MRSA, ESBL
producing bacteria and VRE.
Source:
Reflection paper on the risk of antimicrobial resistance transfer from companion animals
http://www.ema.europa.eu/docs/en_GB/document_library/Scientific_guideline/2013/10/WC5
00152665.pdf