The study was conducted by researchers from Johns Hopkins Center for a Livable Future and the Bloomberg School of Public Health, in Baltimore. By analyzing feather meal from animal feedlots, the researchers found evidence that many of the chickens had been fed fluoroquinolones, which were banned for use in poultry in 2005.
The FDA banned the use of fluoroquinolones after determining that the antibiotics were contributing to the rise of antibiotic-resistant Campylobacter bacteria, which can cause Campylobacteriosis.
Campylobacteriosis is a common cause of diarrhea, which is sometimes bloody. Other symptoms include cramping, abdominal pain and fever, nausea and vomiting. The illness usually last for two to five days, but can sometimes last up to 10 days. Long-term complications are rare but can include arthritis and a nerve condition called Guillain-Barre syndrome where the body’s immune system begins to attack the nervous system. The condition lasts for several weeks and usually requires intensive care. About 124 deaths are attributed to campylobacteriosis each year.
The researchers examined 12 samples of feather meal from across the country and found that 8 of the 12 contained banned antibiotics. The researchers say that signs of the drugs in the feather meal is evidence that the antibiotics were fed to the chickens before they were slaughtered. They also found signs of acetaminophen, the active ingredient in Tylenol, as well as the active ingredient in Prozac. Caffeine was also found in 10 of the 12 samples.
The same researchers reported to the National Center for Biotechnology Information that the samples also contained arsenic, raising questions as to whether feather meal or chicken products represent a previously unrecognized source of arsenic into the human food supply.
The study comes as the FDA continues to push for an overall reduction in the use of antibiotics among livestock.
On April 11, the agency released a final guidance on what it considers the judicious use of antimicrobial drugs in livestock (pdf). The guidance calls for the phasing out of the agricultural production use of antimicrobials and for the industry to begin using veterinary oversight of the therapeutic use of drugs in food-producing animals.
The FDA also issued draft guidance (pdf) on how drug companies can voluntarily remove the use of antibiotics and a draft proposed Veterinary Feed Directive regulation that guides veterinarians on how to authorize the use of certain animal drugs in feed. Both the draft guidance and draft rule are open for public comment. All three documents will be posted in the Federal Register.
A press release by the National Chicken Council pushed back on the Johns Hopkins study and how it was reported in the media. Tom Super, vice president of communications, said that sample contamination and a misunderstanding of chicken feed could account for some of the findings.
Super stated there were other antibiotics found in the chickens that have never been knowingly used in the poultry industry, raising questions about the validity of the study.
“Modern testing methodologies, like those used in this particular study, are extremely sensitive and can detect bioaccumulation of just about anything — even if the compound or antibiotic has not been used in years or was never used,” Super stated in the press release.
As for the arsenic, Super said that could be explained by Roxarsone, an ingredient in chicken feed that included organic arsenic which was removed from the market last year. Organic arsenic differs from inorganic arsenic, which is typically considered poisonous.
Super said the one thing the public should take away from the study is that the researchers themselves found that there was nothing in the samples that was a threat to public health.