Scare-mongering not productive approach to antibiotic discussion

For me, that occurrence stems from the most recent antibiotic symposium sponsored by the National Institute for Animal Agriculture (NIAA); the symposium addressed antimicrobial resistance from a One Health perspective including representatives from the food production industry, human medicine and public health.

My breaking point occurred as I was making my way home from the conference, thus the topic was top of mind. Coincidentally, I stumbled across that day’s Fresh Air episode featuring Maryn McKenna discussing her new book, Big Chicken.

The book is hyped as an “eye-opening expose. McKenna documents how antibiotics transformed chicken from local delicacy to industrial commodity –- and human health threat.” Host Terry Gross picked right up on that theme. She opened the show with the following:

“We’ve been told that resistance is partially a result of doctors overprescribing antibiotics. But it might be more connected to the use of antibiotics in livestock…In the U.S., meat animals consume four times the amount of antibiotics that people do, so if doctors are being warned about overprescribing antibiotics, well, what about the livestock industry?
Clearly, Gross hasn’t done her homework with respect to the data.”

The “four-times” reference is a tired talking point. Even the Food & Drug Administration notes that sales and distribution data “does not represent how much or in what way these drugs are ultimately used.” Moreover, FDA also warns that, “Before comparing human and animal sales and distribution data, there are several differences in the circumstances of use of antimicrobial drugs in human and veterinary medicine that must be carefully considered.” Lastly, nearly 40% of total antibiotic sales designated for food-producing animals are classified as “not currently medically important.”  So much for factual context.

Nonetheless, Gross then asked McKenna, “So how often do scientists think…[resistant] bacteria is passed along, not just through the meat but through dust or through the water, through clothing?”  In other words, how well do we understand the transmission process? McKenna hedges the answer: “Right now I think it’s quite hard to predict the probability…”  Precisely. We don’t fully understand the transmission process.

But there’s more. Gross explained that, “One of the things that really astonished me in your book is that some infections that you wouldn’t think have anything to do with chickens might have something to do with chickens, like UTIs, urinary tract infections. What is the connection between UTIs and resistant bacteria from chickens or livestock?

McKenna expands on the drama:

“…because so many people get UTIs so often, 6 to 8 million UTIs in women in the U.S. every year, that woman might go back to her doctor and the doctor will presume that she’s been re-infected as opposed to the UTI never having been cured at all….And one pretty good estimate now is that of those 6 to 8 million UTIs that occur in women every year in the U.S., possibly 10% could be foodborne UTIs, could be due to this antibiotic-resistant bacteria traveling from farms….”
The key words above being “might” and “possibly.” There are no certainties here.

Nevertheless, it’s an easy bandwagon to jump on. For example, one Boston radio station hyped the McKenna book-tour conversation as follows: “How antibiotic resistance moves from farm to fork.” That’s a troubling lead-in. One, resistance transmission is NOT clear cut. And two, even if it were, providing an authentic explanation amidst the scientific complexity just isn’t possible in a 12-minute interview.

To that end, Dr. Laura Kahn, Princeton University, and author of the book, One Health and the Politics of Antimicrobial Resistance, was one of keynote speakers at the NIAA symposium.  Several items in her presentation are key to this discussion and demonstrate the enduring challenge towards understanding antibiotic resistance:

1.     Avoparsin (chemically similar to vancomycin) was banned in 1997 in the EU – largely the result of a rise in VRE (vancomycin-resistant enterococci) incidence in food animals.

2.     Following the ban, there have been NO consistent trends in VRE isolates from hospitalized humans following.

3.     Based on the most recent research, hospital-associated VRE appears to be genetically distinct from VRE in livestock.

All this brings to mind the delineation aptly articulated by Dr. Scott Hurd (former deputy undersecretary for food safety, now deceased): “concern” and “risk” are two very distinct concepts.  Establishment of risk mandates identification of the causal pathway where resistant pathogens cause lack of therapeutic responsiveness.  In other words, concern is a relatively general, vague and non-quantifiable concept — risk is a specific, measurable and verifiable concept.

It goes without saying, antibiotic resistance represents a very serious, complex public health consideration. There’s work to be done.  Long-term solutions will require ongoing research, surveillance, and comprehensive collaboration.

Unfortunately, over-simplified storylines and scare-mongering are easy to exploit. Sure, it gets attention and sells books. However, it misses the mark for what’s really going on –- and in the end proves to be a public disservice. So while the cows are getting out, that approach wants only to shut the gate because it’s easy and avoids what’s really needed –- the hard work of fixing fence.


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