According to the just released Centers for Disease Control and Prevention “Antibiotic Resistance Threats in the United States” report, the number of annual deaths in the U.S. attributable to antibiotic-resistant infections has dropped from an estimated 44,000 in 2013 to 35,000 in 2019. Notably, the ever-popular but biologically nebulous term “superbug” does not appear on a single page in the report. That wasn’t the case for a recent column in this paper (Oct. 18) and I want to address a couple of fallacies perpetuated by that column and by others.
First, meat sold from USDA-inspected facilities is not “laced with antibiotics” and this has been true for many decades. Veterinary antibiotics have well-defined “withdrawal times,” meaning periods of time needed to allow the antibiotic to be metabolized or excreted from treated animals. It is patently illegal to sale food products before withdrawal times are met, and failure to adhere to withdrawal times is taken very seriously. Not only can regulators eventually shut down offending businesses, but even the perception of such abuse can have significant consequences for the affected industries. It simply isn’t worth the gamble.
When you go to your favorite sandwich franchise and you see posters advertising “antibiotic-free chicken,” they are telling you that antibiotics were not used when the animals were produced … and this is primarily the case for broiler chickens that have very short growth-to-harvest periods. This claim is also applicable to the meat itself and this might make consumer happy, but this fact is no different from alternative products.
Another common claim is that animals are fed antibiotics to increase their rate of growth. Thanks to new rules from the FDA (Guidance No. 213) and industry cooperation, as of January 2017 medically important antibiotics can no longer be used for the purpose of stimulating growth. Furthermore, food producers cannot administer antibiotics to food animals via food and water without a prescription from a veterinarian. Since these changes were implemented, the FDA reports that domestic sales of medically important antibiotics for food animals have decreased by 43 percent (i.e., 4,568 fewer tons) between 2015 and 2017.
Another common refrain is that it is irresponsible to use antibiotics for “disease prevention” in food-animal production. Nevertheless, just as different antibiotics and administration practices can have very different outcomes with respect to antibiotic resistance, different disease prevention practices can have very different effects. Consider a 2016 study of feedlot cattle that was published in the journal Applied and Environmental Microbiology. Upon arrival at the housing facilities 150 animals were treated with a 5-day course of an old-line antibiotic (chlortetracycline) to help prevent pneumonia that commonly occurs after animals are transported (“shipping fever”). Another 150 animals were not treated.
The effects of treatment had very limited and short-term impact on the number of tetracycline-resistant bacteria in these animals. More importantly, only two animals out of 150 developed pneumonia and had to be treated with more potent antibiotics. In sharp contrast, 25 percent of the untreated animals developed pneumonia and had to be treated with one of three much more potent antibiotics. In short, if we don’t use preventative treatments in some situations, not only is there an animal welfare crisis, but producers have to pull out the big guns to treat the animals … with potential for favoring resistance to more potent antibiotics.
The U.S. population is going to continue relying on animal agriculture for the foreseeable future. One way to reduce the need for antibiotics is to develop new vaccines and husbandry strategies that either prevent disease or that reduce the likelihood of disease transmission. Biotechnology has tremendous potential where, for example, a very minor change to one DNA sequence in a cow could render the animal nonsusceptible to one of the most important pathogens that causes shipping fever. Less pneumonia means less need antibiotics.
Developing these alternatives requires investment, but such investment in the U.S. is pretty pathetic. The primary funder for university-level animal disease research is the U.S. Department of Agriculture. The 2019-20 USDA program for “Animal Health and Production and Animal Products,” totals about $37 million, but these funds are divided between five different programs of which disease research is only one. With this paltry investment, don’t count on making antibiotics obsolete in the near future.
And if you think $37 million divided into five programs is a large investment, contrast this with the estimated $110 million that taxpayers have invested in President Donald Trump’s golf games (so far). Our priorities are warped to say the least.
Douglas Call is a microbiologist. He and his family have lived on the Palouse for more than 20 years.