However, what concerns me is the misinformation they are using to promote FDA’s action. This information may damage my patients, the animals. I understand it makes good headlines, but they know good policy cannot be made with a 20-second sound bite or an inflammatory headline. Therefore, I must correct some of information about on-farm antibiotic use. I will use the Wired article as basis for discussion.

First, the picture of drugs on a plate is an inflammatory and inaccurate visual which distorts the truth. Additionally, it is not even related to the real concern here: bacteria resistant to a specific antibiotic due to on-farm use. As we recently discussed on this blog, current FDA regulations on drug use require animal treatment to be discontinued in time for the medicine to leave the system (called a withdrawal period). USDA, which collects data every year, shows the withdrawal systems works very well. So THERE ARE NO DRUGS ON THE DINNER PLATE.

I do not support antibiotic overuse or misuse in agriculture or any other field, including human medicine. Thirty years ago, when I started veterinary practice, we were well-trained in prudent antibiotic use techniques, as antibiotics are a valuable on-farm resource to keep animals healthy until arriving at your dinner table. However, the companies which sell antibiotics report that only 13 percent of all product sold were sold under the “performance enhancement,” or growth promotion, label. The rest is for animals who need medicine to prevent and treat illness! Therefore, looking at the total volume of product sold is not meaningful to this debate. Although everyone continues to harp on this 80 percent number, it is important to understand that there are many more livestock in the U.S. than there are people; most are larger and need a larger dose. Also critical to this discussion, the types of antibiotics used in humans are much different than those used in animals.

My biggest concern is this broad-brush antibiotic bashing will harm my patients, the livestock who feed us. Readers need to understand that a livestock production is like running a day care or nursery. It is full of fresh, fragile babies.  When a pig goes to market, it is only six months old and a chicken is only six weeks old! Whether they are raised indoors or out, organic or conventional, they all can get sick. It is wrong and unethical to withhold that treatment.

At the recent state fair, a turkey grower told me of removing 300 dead birds from his barn in one morning. They had “MG,” and he could not get the correct antibiotic. Drug companies are moving out of the animal health business due to the silly ideas like those in the Wired article and many others. Most of the antibiotics used on-farm are because sick and dying animals need medicine, not so the farmer can make a quick buck. ANIMALS NEED MEDICINE ALSO.

Point: “Antibiotics are integral in the treatment of many foodborne diseases, making this an important issue for the food safety community.”

Counterpoint: Yes, antimicrobial resistance (AMR) is a big deal. Antimicrobials are used in treating infections. However, they are not the first line of defense for treating foodborne illness, even in cases requiring hospitalization. Instead, the primary course of treatment is fluid therapy (2). Therefore, even if we could erase AMR in foodborne pathogens, it is unlikely that there will be a significant improvement in the outcome of foodborne illness cases.

Point: Drug-resistant infections take a staggering toll in the United States and across the globe. Just one organism, methicillin-resistant Staphylococcus aureus (MRSA), kills more Americans every year than emphysema, HIV/AIDS, Parkinson’s disease and homicide combined. Nearly 2 million Americans per year develop hospital-acquired infections (HAIs), resulting in 99,000 deaths – the vast majority of which are due to antibacterial-resistant pathogens. Two common HAIs alone (sepsis and pneumonia) killed nearly 50,000 Americans and cost the U.S. health care system more than $8 billion in 2006.

Counterpoint: The impact of AMR is staggering. Resistant infections have been a problem since the discovery of penicillin, which is the reason for the invention of multiple types of antibiotics (3). It is also important to realize that very few of the bacteria listed in the above paragraph are related to livestock and food. In addition, several other medically important bacteria, such as Pseudomonas aeruginosa, Streptococcus pneumoniae, and Mycobacterium tuberculosis, have resistance patterns that cannot be explained from livestock antimicrobial usage (4).

Point: “Antibiotics are becoming less and less effective, in part due to over-prescription and inappropriate use.”

Counterpoint: I don’t really disagree with this point, but I would like to “fine tune” it a bit. As soon as an antibiotic is first used, resistance begins to develop. Bacteria evolve under the selection pressure of antibiotic exposure. It is how they survive. Inappropriate or unnecessary use means extra pressure on the bacterial population, thus increasing the speed of evolution.

To the extent that agriculture is guilty for antimicrobial resistance, we repent. It is important to note that many producer groups are making major efforts to become more prudent in antimicrobial use, just like what is being done in human medicine.

Point: “If I am reading scientists correctly, there are multiple theories for antibiotic resistance and agreement that some occurs naturally in the environment. Some of these theories involve antibiotic uses by both humans and animals.”

Counterpoint: Both points are correct. The ability to resist antibiotics has been around since the first microbe. Many types of antimicrobial resistance were recently discovered in four million-year-old dirt that had never been touched by man or beast (5). Subsequently, any antimicrobial usage, even if appropriate, allows the resistant strains to become more prominent.

Point: “Yet, is it just me, or is antibiotics used in animal agriculture the only thing we hear about when antibiotic resistance comes up? Am I wrong to look at antibiotic resistance as a big circle with animal issues maybe involving a 25 percent slice with lots of other unknowns out there?”

Counterpoint: No counter argument here. You are correct! Agriculture is taking way too much of the heat for its contribution to antibiotic resistance, and all published risk assessments show this contribution to be negligible. I would venture to say the percentage is much less that 25 percent. One paper I published shows the average American is more likely to die from a bee sting (one in six million) than to get a few extra days of diarrhea due to macrolide (a common animal antibiotic) use in livestock (6,7).

Point: “I just have this feeling that allowing animal diseases to go untreated would not contribute to food safety.”

Counterpoint: Again, I agree. Failure to treat or prevent illness leads to needless animal suffering. Additionally, some new research is showing that healthy animals that have recovered from a respiratory or infectious illness are more likely to be contaminated with foodborne pathogens such a Salmonella or Campylobacter (8,9).

Point: “Antibiotic resistance is complex issue. Help direct our coverage by suggesting people we should talk to and places we should go. Where’s the cutting edge research being done? This is not just some problem on the farm we haven’t solved. It’s bigger, broader and more complex. Now, please submit your answers.”

Counterpoint: Amen brother. There many questions that have not been addressed. If society was not so busy pushing draconian and meaningless solutions such as the PAMTA (Preservation of Antibiotics for Medical Treatment Act) or collecting usage data without good data on resistance, then resources would be available to answer many of your thoughtful questions.

References

(1) Flynn, D. 2012. Letter from the Editor: Antibiotic Resistance.
https://www.foodsafetynews.com/2012/08/letter-from-the-editor-antibiotic-resistance/#.UFeIPbKPU-I

(2) Food Poisoning Center, Sanford, FL. 2011. What is the treatment for food poisoning?
http://www.medicinenet.com/food_poisoning/page6.htm#what_is_the_treatment_for_food_poisoning

(3) D’Costa, V. et al. 2011. Antibiotic Resistance is ancient. Nature 477:457-461
http://www.nature.com/nature/journal/v477/n7365/full/nature10388.html

(4) Bywater, R.J., Casewell, M.W. 2000. An Assessment of the impact of antibiotic resistance in different bacterial species and of the contribution of animal sources to resistance in human infections. Journal of Antimicrobial Chemotherapy 46(4):643-645. http://jac.oxfordjournals.org/content/46/4/643.full.pdf+html

(5) Bhullar, K. et al. 2012. Antibiotic Resistance is Prevalent in an Isolated Cave Microbiome. PLoS One
7(4): 1-11.

(6) Ropeik D. et al. (2002). RISK! A Practical Guide for Deciding What’s Really Safe and What’s Really Dangerous in the World Around You. Houghton Mifflin Company, Boston, 2002.

(7) Hurd, H. S., et al. (2003). The Public Health Consequences of Macrolide Use in Food Animals: A Deterministic Risk Assessment. Journal of Food Protection, 67:5, 980-992.

(8) Hurd, HS, Yaegar MJ, Brudvig, JM, Taylor, DT, Wang, B. 2012. Lesion severity at processing as a predictor of Salmonella contamination of swine carcasses. American Journal of Veterinary Research 73(1):91-97.

(9) Hurd, HS, Brudvig, J, Dickson, J, Mirceta, J, Polovinski, M, Matthews, N, Griffith, R. 2008. Swine Health Impact on Carcass Contamination and Human Foodborne Risk. Public Health Reports. 123:343-351.