The 2017 Canadian Antimicrobial Resistance Surveillance System report was just released, and as always it contains a lot of interesting data. Some are interesting, some are concerning, some are encouraging.
I’m not going to try to distill a 90 page report into a quick blog post, so I’ll cover some highlights separately. Let’s start with the Antimicrobial Use in Animals section. Here are some highlights (and some comments).
In 2016, ~1 million kgs of medically important antimicrobials were distributed for sale in Canada.
- This misses some antibiotics that get used via loopholes, but those are being closed and this number is probably a pretty good overall estimate.
- The great news…that’s 14% lower than 2007 and 17% lower than 2015
600,000 kg of ionophores and chemical coccidiostats were also distributed.
- These are often combined with other antimicrobials (sometimes to make things look scarier) but they are irrelevant from antibiotic-resistance and public health standpoints. So, it’s good to see them separate (and to essentially ignore them).
99% were intended for food animals, on a per kg basis.
- This is always hard to interpret and sometimes leads people to think that companion animals are irrelevant. We have to be a bit wary focusing just on per kilogram data (1 kg of antibiotic treats a lot more Chihuahuas than cattle). The main antibiotic classes used in companion animals were cephalosporins, beta-lactams and trimethoprim-sulfa, all drug classes of high importance.
- What this shows to me is that we can have a huge impact on overall use focusing on food animals. However, the drugs that are used in pets are often the same as those used for serious infections in people, and we share bugs readily with our pets. So this numbers shouldn’t be taken as an indication to ignore them.
Fluoroquinolones decreased by 56% from 2015 to 2016.
- Wow. That’s great, since this is one of the biggest classes we’re worried about. They’re important drugs (for both humans and some animal species) but are prone to overuse.
Most of the distributed antibiotics were those intended for use in feed, accounting for 76% overall. On the opposite end of the spectrum, intramammary drugs (used for mastitis in cattle) accounted for <1%.
When everything is put together on a per kg basis, 78% of antimicrobials distributed or sold in 2016 were for food animals, 20% were for humans, 1% for crops and 1% for companion animals.
- Again, be somewhat wary of crude kg numbers (since the relevance of a kg of tetracycline is probably much, much less than a kg of a fluoroquinolone) and there are approximately 19 times more animals in Canada (excluding farmed fish) than humans, but they give some idea of how we use antimicrobials in this country and they give us numbers for comparison over time. (The 2nd figure below is an interesting one to think about.)
Some people will take these numbers and use them to spin certain agenda. However, we’re better off using them as the basis for more surveillance, more interventions and more research to reduce and improve use of antibiotics in Canada, whatever species they go into.