As families across America adorn their dinner tables with plump, juicy turkeys this Thursday, they've likely given little thought to what their future food previously consumed.
By the end of this year, an estimated 248 million turkeys will have been raised in the U.S., approximately 83 percent on farms that produce more than 60,000 turkeys each and most eating a diet that includes low doses of antibiotics. This common agricultural practice results not only in more meaty birds, according to experts, but also in greater risks to public health.
"Antibiotic use in animals comes back to haunt people," said Stuart Levy, a Tufts University microbiology professor who focuses on antibiotic resistance. He recently co-authored a review of the evidence showing how animal antibiotics affect human health -- via direct contact and indirectly via food, water, air and anywhere manure goes.
Levy and other experts warn that the widespread use of antibiotics to treat sick livestock, prevent the spread of disease in cramped conditions or simply promote animal growth has fueled the proliferation of antibiotic-resistant bacteria, which is making many infections in humans harder to treat. As The Huffington Post reported in August, some human infections now resist multiple antibiotics.
Livestock receive an estimated 80 percent of the nation's antibiotics. According to the U.S. Food and Drug Administration, about 90 percent of those antibiotics are consumed by the animals in their feed or water -- usually at very low doses. What doesn't kill bacteria, however, often makes them stronger and more likely to defeat medicine's current range of weaponry.
"Turkey is one of the most frequently contaminated meats," said Ellen Silbergeld, a professor at Johns Hopkins School of Public Health. She highlighted a study from earlier this year that found 77 percent of turkey samples collected from U.S. supermarkets tested positive for the bacteria Staphylococcus aureus. Of those, approximately 96 percent were resistant to at least one antimicrobial agent. A few of other recent studies hint at the growing problem of multidrug-resistant infections, such as methicillin-resistant Staphylococcus aureus (MRSA), in meats sold to consumers, including turkey.
Still, members of the agricultural industry dispute the role that drugs for livestock play in developing antibiotic resistance.
"It is not surprising to find Staphylococcus bacteria anywhere you want to look," said Richard Carnevale, vice president for regulatory, scientific and international affairs at the Animal Health Institute, which represents pharmaceutical companies. "It is a ubiquitous organism."
"A turkey farmer's number one priority is to ensure the health and well-being of their flocks," noted Sherrie Rosenblatt, a spokesperson for the National Turkey Federation. While she suggested that the industry supports any efforts to improve safety for consumers, she added that "there is no conclusive evidence that antibiotic use in animals is affecting human health."
Turkey growers use only approved antibiotics, said Rosenblatt. And Carnevale noted that about 40 percent of these compounds are not used in human medicine.
Complicating that math, however, is the recently recognized ability of bacteria to share. Bacteria in meat can pass on their resistance to other bacteria in a person's gut, for example, creating bacteria that are resistant to drugs that may never have been used on the farm.
Ground turkey is a common culprit, as evidenced by food producer Cargill's pair of recalls earlier this year. Salmonella and other bacteria that tend to make people sick -- but not necessarily turkeys -- live inside the bird's intestinal tract. "When they are ground up, essentially everything becomes the outside of the bird," said Gail Hansen, senior officer with the Pew Campaign on Human Health and Industrial Farming.
But this doesn't mean consumers should throw up their hands and stop taking steps to protect themselves as they roast whole turkeys. Silbergeld stressed the importance of thoroughly cooking the meat and preferably preparing the stuffing separately. And look for a turkey with an organic or antibiotic-free label, said Hansen.
The latter action could affect more than the consumer's own dinner table, Hansen suggested. "The market isn't going to change unless they know they are going to sell" the antibiotic-free variety.
The FDA has issued a draft "Guidance on the Judicious Use of Medically Important Antimicrobial Drugs in Food Producing Animals." It offers suggestions to industry rather than imposing a ban. As the FDA explains in its recent rejection of public petitions to eliminate the use of certain medically important antibiotics in livestock, the agency has yet to identify enough evidence to take that stricter step.
The U.S. Government Accountability Office recently reported that there has been "limited progress in improving data collection on antibiotic use and resistance" and that "without an approach to collecting more detailed data, [the U.S. Department of Agriculture] and [the U.S. Department of Health and Human Services] cannot track the effectiveness of policies they undertake to curb resistance."
"It's a shame that after all these years the U.S. is still caught flat-footed," said Rep. Louise Slaughter (D-N.Y.), the only microbiologist in Congress, in a recent statement. "We've known that this is a problem for quite some time. And we're totally unprepared to deal with the growing threat of antibiotic resistance, as was confirmed by the GAO, by not even collecting the necessary data. The American public should be outraged."
Slaughter is the author of the proposed Preservation of Antibiotics for Medical Treatment Act , legislation that seeks to preserve the effectiveness of antibiotics for the treatment of human disease. Originally introduced in 2007 and since re-introduced, the act currently has 70 co-sponsors and hundreds of endorsing organizations -- from the American Medical Association and the Natural Resources Defense Council to the Humane Society.
"There is no indication that the committee even plans on holding a hearing," Shurid Sen, a spokesperson for Slaughter, told HuffPost. "But we are hopeful that they will begin to take the issue seriously."
Meanwhile, the European Union continues to move forward with phasing out nontherapeutic use of antibiotics in livestock. What's more, noted Silbergeld, the Europeans have been able to do it without any major impacts on productivity or the cost of food in the domestic market.
"This does seem to be a case where we can have our turkey and eat it too," Silbergeld said.
CORRECTION: A previous version of this story spelled a source's name Hanson rather than Hansen. The error has been corrected.