Source: American Dairy Science Association
By Nevil Speer, PhD, MBA
There’s a lot of misinformation out there among the general public about food and food production. And a lot of that can be shaken off and we move forward in a constructive manner. But if there’s one issue where agriculture really takes it on the chin it’s about the use of antibiotics in livestock.
That’s not surprising; when two critically-important, complex issues come together into the crucible there’s potential for lots of misdirection. That’s unfortunate, though, because the judicious use of antibiotics (or lack thereof) and potential for antibiotic resistance is a matter of public health – it touches us all in some form or fashion. That importance underscores the necessity of having genuine, science-based discussion around the issue. Smoke and mirrors won’t suffice. Nonetheless, the issue has come to the forefront in recent months.
First, there was the lawsuit filed by a coalition of public interest groups. The suit asserts the Food & Drug Administration has violated federal law by failing to actively withdraw approval of penicillin and tetracycline usage in animal feed for non-therapeutic, growth-promotant purposes despite claims FDA previously concluded that such tactics facilitate development of antibiotic-resistant bacterial strains. Hence, the suit is predicated on the claim of, “…growing evidence that the spread of bacteria immune to antibiotics has clear links to the overuse of antibiotics in the food industry.”
Dovetailing that effort came proposed legislation in both the House and Senate aimed at reduced antibiotic use in animal agriculture. The bills are primarily designed to phase out non-therapeutic use of antibiotics in livestock. The talking points are the same. For example, Dianne Feinstein (D-CA), upon reintroduction of the legislation: "The rampant overuse of antibiotics in agriculture that creates drug-resistant bacteria, an increasing threat to human beings….The effectiveness of antibiotics for humans is jeopardized when they are used to fatten healthy pigs or speed the growth of chickens.”
So the logic is this: antibiotics are utilized in farm animals, resistant strains of bacteria fail to be contained and thus escape the farm, the public is subsequently exposed to such bacteria via various avenues (including consumption of meat), citizens eventually become ill, and ultimately the illness is unresponsive to treatment. Therefore, you see efforts to curtail ongoing use in food production settings and pre-empt approval for new antibiotics and/or uses of currently existing antimicrobials in livestock.That all sounds simple enough. And the average citizen hearing that type of rhetoric is going to immediately assume that such litigation and legislation is necessary.
However, the issue isn’t that simple. As mentioned above, it’s a public health issue and the matter of resistance can’t end simply with removing subtherapeutic use of antibiotics in livestock production; the solution is only as good as the weakest link. There’s no sense in limiting use on the farm if medical misuse is also not going to be curtailed. The issue must be addressed comprehensively, not to mention that there’s never been a scientifically documented link between antibiotic use in livestock and increasing risk of bacterial resistance in humans.
Therefore, lawsuits and legislation simply make agriculture a political scapegoat; that’s a disservice to the broader public - it’s disingenuous, inappropriate, and most importantly, ineffective. In fact, to the contrary, Hurd et al. (Journal of Food Protection, 2004) demonstrated in their farm-to-patient risk assessment the use of antibiotics in farm animals represents a “very low risk of human treatment failure” - depending on the pathogen assessed the treatment failure risk ranged from 1 in 10 million to 1 in 3 billion.
The medical community must take part in this conversation. Most notably, antibiotic prescription practices must be addressed. Frivolous treatment has become increasingly widespread. Numerous studies reveal that patients expect antibiotics (regardless of appropriateness – the desire of to preempt any secondary infection). Doctors, often time-crunched and motivated to maintain their respective patient base, often acquiesce to patient pressure. The system is designed around the individual patient – public health concerns about potential resistance go unaddressed amidst the individual doctor-patient relationship. Moreover, none of this addresses misuse of antibiotics (failing to take the full course and subsequently saving for some later illness) once the prescription is in hand.
Lest we forget, resistance is not a new phenomenon and was on the radar screen long before antibiotic use was regularly implemented in livestock production. Maryn McKenna (Superbug, c. 2010) explains it like this:
Penicillin [released to the public in 1944] was a wonder drug, the first glimpse of the antibiotic miracle that would quell the ancient scourge of infectious disease, and its inventors were heroes. A portrait of [Sir Alexander] Fleming appeared on the cover of Time in May 1944 over the caption:“His penicillin will save more lives than war can spend.”
The drug cut cases of syphilis and deaths from pneumonia by 75 percent and deaths from rheumatic fever by 90 percent. It did so well against serious diseases that its benefits were shared around for minor problems too. It was freely sold over the counter, in mouthwash, sore-throat lozenges, first-aid ointments, even cosmetics. In the United States, it was not made prescription-only until 1951. Fleming himself predicted what would happen next. In his speech accepting the Nobel Prize in December 1945, he said:
“There is the danger that the ignorant man may easily under-dose himself and by exposing his microbes to non-lethal quantities of the drug, make them resistant. Here is a hypothetical illustration. Mr. X has a sore throat. He buys some penicillin and gives himself, not enough to kill the streptococci but enough to educate them to resist penicillin. He then injects his wife. Mrs. X gets pneumonia and is treated with penicillin. As the streptococci are no resistant to penicillin the treatment fails. Mrs. X dies.”
Fleming was sadly right, though amidst the joy over penicillin’s impact, the research that would prove his prediction received little publicity. In December, 1940, before the drug had ever been tested in a human, [biochemist Ernst] Chain and his Oxford University colleague Edward Abraham said in a letter to the journal Nature that the common gut bacteria E. coli seemed to be evolving a defense against the new drug and was producing an enzyme that kept penicillin from working. Two years later, Charles Rammelkamp and Thelma Maxon of Boston University demonstrated experimentally that staph bacteria could also develop protection against the effects of penicillin.
At the end of the day, strict focus on eliminating use of subtherapeutic antibiotic use in livestock is a case of target fixation (fixated on the target – livestock lest we forget to take necessary action to avoid the dangers of collision – widespread resistance). We can try to be like Denmark but that fails on several counts: First, it’s not effective in eliminating antibiotic use at the farm level; we can try to be like Denmark and completely eliminate the subtherapeutic use of antibiotics in livestock production. The Denmark experience reveals that therapeutic use of antibiotics to treat animal disease increased over 200 percent between 1998 and 2009. Second, there’s been no documentation of antibiotic resistance in humans has declined. Lastly, it completely overlooks the human side of the issue.
General perception that somehow, someway A new rule always makes everything better….but does it? In this case, most definitely not!!!
Lulling general public into a false sense of security!
Dr. Nevil C. Speer is with Western Kentucky University and serves as the chairman of the Animal Agriculture Advocacy Council for the National Institute for Animal Agriculture, a national organization devoted to engaging livestock producers and livestock health professionals in developing solutions for issues in the livestock industry.