Letters: Antimicrobial use in food animals
After reading the "Mind Over Miller" editorial, "An accurate and unfortunate prediction," in the October 2011 issue, and as president of the American Veterinary Medical Association and a small-animal practitioner, I felt the need to provide information in response to the first statement made in the editorial.
Dr. Miller states, "Research by the Translational Genomics Research Institute in Arizona recently found that 47% of beef, pork, and poultry meat samples harbored Staphylococcus aureus and that 52% of the staphylococci were antibiotic-resistant. The cause of this potentially disastrous problem is the indiscriminate feeding of antibiotics to healthy livestock, a custom since the mid-20th century."
While I understand consumers are very concerned about the safety of our food supply and the use of antimicrobials in food animals, it is important to not jump to unproven conclusions based on speculation. The United States currently has the safest, most abundant, and most affordable food supply in the world. This success is due in large part to veterinarians balancing the health and welfare interests of the animals with the judicious use of medications, knowing that healthy animals produce a safe and healthy food supply.While antibiotic-resistant S. aureus has been found in retail meats, the Centers for Disease Control and Prevention has clearly stated that it is not a foodborne hazard: "Studies over many years have found antibiotic-resistant organisms, such as methicillin-resistant Staphylococcus aureus (MRSA), in a variety of food products including retail meats and raw milk. While more study is needed to understand whether MRSA in foods and food animals plays a role in human infection, to date, there have not been any documented cases of people getting MRSA from eating food that contains MRSA. Rather, MRSA is usually spread directly from person to person."1
In addition, the strains of MRSA found in retail meat samples that have been typed have not been livestock-associated strains, suggesting that the source of the contamination is a human source, perhaps during processing. Further information can be found at http://cdc.gov/drugresistance/organisms/mrsa-and-food-products.html.
It must be remembered that we continue to monitor and improve upon the judicious use of antimicrobials in food animals, while also protecting the safety of that food supply and the health of people who consume these products. If these medications were not available for use in animals, the consequences would be much worse for the animals and for food safety until newer antibiotics or alternatives to antibiotics become proven and available. We are working with the Food and Drug Administration to increase veterinary medical oversight of antimicrobials, even as the rigorous monitoring system currently in place in the U.S. continues to safeguard both the welfare of the animals and the safety of our food supply.
Finally, speaking as a small-animal practitioner and a consumer of food products both in restaurants and from a variety of grocery store outlets, I have complete confidence in the safety of our U.S.-origin food supply, especially that of animal origin, because I understand the precautions taken, as well as the fact that appropriate handling and cooking of raw meat should eliminate any risk of bacterial transmission to people. Many of the recent food-safety issues have arisen from products that are not cooked before consumption and are not associated with the use of medications in livestock in any way.
René A. Carlson, DVM
1. Centers for Disease Control and Prevention. MRSA and food products. Available at: http://cdc.gov/drugresistance/organisms/mrsa-and-food-products.html. Accessed January 11, 2012.
Dr. Miller responds: While I agree with Dr. Carlson that the United States has an incomparable record of food abundance, supervision, and safety, that doesn't alter the fact that the indiscriminate use of antibiotics inevitably produces resistant organisms. We have, in effect, selectively bred, even if unintentionally, microorganisms resistant to commonly used antibiotics, such as MRSA. And MRSA is not the only such organism. Certain strains of Mycobacterium tuberculosis are now drug-resistant, as are some organisms that cause sexually transmitted disease. More such problems are expected—and to be feared.
Antibiotics are one of medicine's greatest discoveries, perhaps only second to vaccines in controlling human and animal communicable diseases. But they should be used selectively and judiciously.
Robert M. Miller, DVM