Mar 18, 2004 (CIDRAP News) – The Food and Drug Administration (FDA) moved a step closer this week to banning the use of a fluoroquinolone antibiotic in poultry on the ground that the drug promotes the rise of antibiotic-resistant bacteria that can harm human health.
FDA Administrative Law Judge Daniel J. Davidson approved the agency's proposal to ban the use of enrofloxacin (Baytril) in poultry. Bayer, the drug's manufacturer, has 60 days to appeal the ruling to the commissioner of the FDA and said it plans to do so.
In a 70-page ruling, Davidson agreed with the FDA's assertions that the use of enrofloxacin has caused an increase in fluoroquinolone-resistant Campylobacter on poultry. He also determined that the levels of fluoroquinolone-resistant Campylobacter in poultry are high enough to cause illness in humans.
"The preponderance of the evidence establishes that fluoroquinolone-resistant Campylobacter results in an increased severity of campylobacteriosis in humans," Davidson wrote.
The FDA first announced its intention to ban the use of fluoroquinolones in poultry in October 2000. In response, Bayer requested a hearing on the proposal. Abbott Laboratories, maker of sarafloxacin, another fluoroquinolone used in poultry, voluntarily accepted the FDA proposal and withdrew the product.
Davidson held hearings on the issue in late April and early May of 2003 and subsequently received briefs from the FDA, Bayer, and the Animal Health Institute, a trade group of firms that make animal drugs.
In his ruling, Davidson wrote that no single study cited by the FDA is sufficient to make the case against enrofloxacin use. However, he stated, "When the record is viewed in its entirety, there is [a] substantial body of evidence supporting the conclusion that the increase in fluoroquinolone-resistant Campylobacter and resultant campylobacteriosis is a result of the extensive use of enrofloxacin in poultry."
Davidson acknowledged that there are other sources of fluoroquinolone-resistant Campylobacter besides poultry, but the weight of the evidence shows that the resistant microbes come mainly from poultry.
Davidson also concluded there is no evidence that enrofloxacin use in poultry offers any significant benefit for human health. He wrote that the drug is effective in treating Escherichia coli infections in broiler chickens and E coli and Pasteurella multocida infections in turkeys, but there are other drugs that can be used. He also called fluoroquinolones the drugs of choice for treating Campylobacter infections in humans.
In announcing plans to appeal the ruling, John B. Payne, president of Bayer Healthcare LLC's Animal Health Division, stated, "Having made a strong scientific argument during the hearing process, we are surprised and disappointed in the Administrative Law Judge’s decision. We believe that the human health benefits of Baytril were not fully considered when arriving at his decision."
The Bayer statement said enrofloxacin is used to treat air sacculitis, a pneumonia-like infection in poultry. The company said it based part of its case on new data showing that "weight variations in birds with air sacculitis contribute to errors in processing that lead to increased levels of bacterial contamination." The new findings "clearly identify the human health benefit and the need to have Baytril available to fight disease and, thereby, ensure a healthy food supply," the company said.