For reference, 80% of antibiotics used in the US are used in agriculture [1]. Animals are fed antibiotics to prevent infection, but they’re also fed to animals as “growth promoters” [2].
60% of infectious diseases in humans originate in animals, and 75% of emerging infectious diseases in humans originate in animals [3].
Point (2) is no longer true as of 2017 (in the US, 2006 in the EU) [1]. I'm happy to see the FDA getting on top of this regulation. Now let's end careless spraying of antibiotics on crops. [2]
Re: Point (2), it's going in the right direction, but at least in Denmark it is very much used in a "preventative" manner in the pork industry. It took a dive when the regulation came into effect, but in the last few years not much have happened, and we still have a MRSA problem out of control.
Independent sources say that more than 90% of all farms with pigs have an MRSA infection. The butcheries reported in 2014 that 88% of all pigs was infected with MRSA. Every 1 in 3 pack of pork is infected and weak and elderly people should be careful with pork in general because of this risk.
It seems horrendous that we would give antibiotics to any livestock in an across-the-board way.
Livestock should only get antibiotics if they come down with an infection and are diagnosed and treated by a veterinarian. If a bunch of the livestock would get sick without preemptive antibiotics then I probably don't think that method of farming should be legal, and I would be glad to pay whatever higher prices would be necessary to abolish it.
Infections were not created by greedy farmers. They occur naturally among all animal populations.
Some quick googling indicates that this practice both increases meat production by 10-30%, and protects animals from a lot of suffering, as they spend their lives mostly healthy.
That said, yeah, we can't keep doing this, and we have to pay the cost. Let's just not pretend there is no cost.
I'm not saying we should cease treating sick animals. I'm saying only treat the sick animals individually after diagnosing them. If that's not practical then let's change farming practices until it is.
(I'm not a farmer. I have no idea what the impact of this practice would be. However, as a naive person I definitely would strongly prefer to reserve the medicinal powers of antibiotics for humans or individually-sick animals, not huge animal populations.)
I mostly agree. This is already done in many countries, and farming goes on there.
My only point is that this isn't done by stupid greedy farmers for no reason. It's a practical and profitable practice that has had a lot of short term benefits both for farmers, consumers and even farm animals. But it also has to end.
I've heard the opinion that most antibiotic resistance genes don't seem to originate in agricultural use.
High AB usage is one factor in developing and spreading resistance, but it's way more complicated. For example the resistance genes also have to jump onto a bacterium that is pathogenic...
> I've heard the opinion that most antibiotic resistance genes don't seem to originate in agricultural use.
Maybe true but I don't see the post you're replying to saying that. If you are saying that, a reference to some research showing that would be welcome.
> but it's way more complicated
surely true, but it doesn't mean antibiotic overuse isn't a damn good starting point for resistance to develop.
This does not back up your claim. Much of it is about lack of evidence on which to draw conclusions. That's clear enough just in the abstract. I'll quote from the abstract. Selectively due to length, but I'll try to be fair:
"The three mechanisms considered are as follows 1: direct infection with resistant bacteria from an animal source, 2: breaches in the species barrier followed by sustained transmission in humans of resistant strains arising in livestock, and 3: transfer of resistance genes from agriculture into human pathogens. Of these, mechanism 1 is the most readily estimated, while significant is small in comparison with the overall burden of resistant disease. Several cases of mechanism 2 are known [so it's been demonstrated to happen], and we discuss the likely livestock origins of [some bacteria] it is hard to assess in robust fashion. More difficult yet to study is the contribution of mechanism 3, which may be the most important of all."
To summarise, a little, some known, and we don't know.
From the summary, and again I'm quoting selectively so be warned:
"The limited data available make it hard to quantify the relationship between antibiotic use in animals and the occurrence of clinical resistance. As we have shown, while there is considerable evidence associating antimicrobial use in agriculture with resistant pathogens in livestock and in the food supply, the evidence for human health risks directly attributable to agricultural antibiotics runs the gamut from speculative to scant"
Summary: possible real threat, too little data to evaluate.
Further, again from the conclusion:
"Once these [antibiotic-resistant] strains have emerged, it might be only a matter of time before they cross the species barrier and adapt to living in humans, at which time there is very little regulation of agriculture can do to prevent their persistence in the clinical setting. The greatest value of reducing agricultural antibiotic use now may be in maintaining a status quo that, while far from ideal, is greatly preferable to the alternative."
Summary: we scientists don't know but we have reason to be very concerned.
These are my selective quotes and my interpretations, but I personally don't see that they support your position.
TL;DR: I read the article mainly as saying basically John Snow knows nothing.
Up to this point the link between agricultural AB usage and human pathogenic infections with resistant strains is quite theoretical and has relatively weak evidence.
60% of infectious diseases in humans originate in animals, and 75% of emerging infectious diseases in humans originate in animals [3].
[1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4638249/
[2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1804117/
[3] https://www.cdc.gov/onehealth/basics/zoonotic-diseases.html