Does the agricultural use of antibiotics contribute to their diminishing effectiveness in people? The debate over Big Agriculture's use of antibiotics is becoming a culture war of facts.
This conflict is of personal interest to me, because I have been deeply involved in research on antibiotic resistance.
Liz Wagstrom, Chief Veterinarian of the National Pork Producers Council says that antibiotic resistance is not an issue. In in a letter to the editor in The New York Times, she writes:
In fact, numerous peer-reviewed risk assessments show virtually no risk to humans from antibiotic use in animals.
...The risk to public health from overuse or misuse of antibiotics comes overwhelmingly from human medicine, not livestock production.
Of course, such an authoritative statement cannot be taken at face value given the inherent conflict of interest that Wagstrom faces as an employee of the pork industry. Dr. Wagstrom was responding to an Op-Ed , "When Food Kills," written by Nicolas Kristoff, in which he wrote:
The Food and Drug Administration reported recently that 80 percent of antibiotics in the United States go to livestock, not humans. And 90 percent of the livestock antibiotics are administered in their food or water, typically to healthy animals to keep them from getting sick when they are confined in squalid and crowded conditions....
We would never think of trying to keep our children healthy by adding antibiotics to school water fountains, because we know this would breed antibiotic-resistant bacteria. It's unconscionable that Big Ag does something similar for livestock.
Consider these facts, described in a commentary I published in Science with my colleague Dr. Peter Oelschaeger:
... it is highly unlikely that an individual living in a developed country could escape any exposure to antibiotics. In the United States, an estimated 8,600 to 13,000 tons of antibiotics (about half of the total consumption) are used for non-therapeutic purposes, including agriculture and animal husbandry (2). A host of antibiotics have been detected in wastewater at levels of 1.7 to 1.9 micrograms/L (3).
This does not prove a causal link between the agricultural use of antibiotics and antibiotic resistance in people. However, the scientific facts seem to support this idea. Literally thousands of tons of antibiotics have been used for agriculture and animal husbandry -- and they are not intended in any way to support public health. Any microbiologist knows that if you grow bacteria in low levels of antibiotics, you can easily select for surviving cultures that have become resistant.
So, is this a culture war of facts? What's your take?
A version of this article was published at Dean's Corner at ScienceBlogs.