Rebuttal by Keep Antibiotics Working to Bayer's False Claims about FDA's Proposed Ban on Fluoroquinolones
On November 19, 2002, messages from more than 16,000 concerned citizens were delivered to Bayer’s new CEO, Dr. Attila Molnar, urging the company to comply with the Food and Drug Administration’s (FDA) proposed ban on using a Cipro-like antibiotic, Baytril, in poultry. FDA proposed the ban based on evidence that such use is spurring the leading bacterial cause of severe food poisoning in humans, Campylobacter, to become increasingly resistant to Cipro.
In response to these and other messages from members of the public, Bayer has distributed materials arguing that FDA’s proposal is unjustified. This memo outlines why Bayer’s assertions are wrong or misleading.
- Bayer assertion: “The rate of Campylobacter infections in humans has decreased 41 percent since the FDA approved Baytril for use in poultry, while chicken consumption in the United States has increased more than 10 percent.”
Response: According to the U.S. Centers for Disease Control (CDC), Campylobacter infection rates declined 27% from 1996 to 2001, not 41% as Bayer claims. The decreasing rate of Campylobacter infections is good news, but this decline is the result of a concerted effort on the part of the U.S. Department of Agriculture, FDA, and others to improve food safety, not the use of Baytril. The bad news is that approximately one in every six Campylobacter infections, or about 19%, is now resistant to fluoroquinolones (the class of antibiotics that includes both Cipro and Baytril). Cipro and other fluoroquinolones are key antibiotics for treating severe cases of foodborne illness. Poultry is the major source of Campylobacter infections in humans in the United States. In recent years, consumers have become increasingly aware that they must carefully handle uncooked meat and poultry to avoid infections from Campylobacter and other foodborne bacteria, and poultry processors have taken steps to reduce contamination of chicken meat by dangerous bacteria. Even so, there are still almost two million cases of Campylobacter infections in the United States each year - resulting in about 100 deaths - according to CDC. Fortunately, most cases do not require antibiotic treatment. However, patients with severe infections and/or those with weakened immune systems - including seniors as well as chemotherapy, transplant, and HIV/AIDS patients - depend on antibiotics to recover. Bayer Corporation should live up to its slogan, “Expertise with responsibility,” and protect the effectiveness of antibiotic treatments for Campylobacter by withdrawing Baytril from the market.
- Bayer assertion: “Latest data from the Centers for Disease Control indicate that the rate of fluoroquinolone-resistance in human Campylobacter cases is virtually unchanged since Baytril was approved in 1996.”
Response: This assertion is wrong. The latest Centers for Disease Control data show a clear increase the rate of fluoroquinolone-resistance in human Campylobacter cases. Although fluoroquinolones (the class of antibiotics that includes Baytril) were approved for use in humans in 1986, resistance to them remained quite low until shortly after these drugs were first approved for use in poultry in 1995. By 1997, 13% of Campylobacter infections were resistant, a figure that rose to 19% in 2001. A recent statistical “trend analysis” by CDC shows that the incidence of fluoroquinolone-resistant Campylobacter infections increased markedly from 1997 to 2001. In addition, a recent study by the University of Pennsylvania has documented an even more marked increase in fluoroquinolone-resistant Campylobacter infections in the Philadelphia area, from zero in 1992 to 40.5% in 2001.
- Bayer assertion: “Foreign travel is the leading risk factor associated with fluoroquinolone-resistant Campylobacter infections.”
Response: The Food and Drug Administration took such infections into account when the agency proposed to ban Baytril use in poultry. Specifically, FDA estimates that 9,261 people in 1999 who needed antibiotic treatment for severe Campylobacter infections had fluoroquinolone-resistant infections as a result of Baytril use in chicken production in the United States. The fact that additional people become infected with resistant Campylobacter because of foreign travel is no justification for ignoring resistant Campylobacter from contaminated chickens in the U.S.
- Bayer assertion: “Fluoroquinolone-resistant Campylobacter was present before the introduction of Baytril for poultry.”
Response: Fluoroquinolones were given to poultry in others countries well before these drugs were allowed for use in poultry in the United States, and as stated above, travelers brought resistant infections back to the U.S. A very small number of additional fluoroquinolone-resistant Campylobacter infections may be attributed to prior use of fluoroquinolones by the infected individual. These two mechanisms can account for the relatively low rate of fluoroquinolone-resistant Campylobacter infections seen in the U.S. before the introduction of Baytril. They do not explain satisfactorily the surge in resistant infections that has occurred since the introduction of Baytril.
- Bayer assertion: “The theoretical human illness rate that the FDA’s Center for Veterinary Medicine attributes to fluoroquinolone-resistant Campylobacter is greatly overestimated. Even if its exaggerated assumptions were correct, the risk the FDA accepts for bottled drinking water is greater than that estimated for Baytril.”
Response: Again, Bayer provides no factual basis for its contention that FDA estimate is incorrect. Indeed, the incidence of foodborne illness in the U.S., including from Campylobacter, is almost certainly underestimated. Many people with food poisoning do not seek treatment and, even if they seek treatment, may be given an antibiotic without being tested to determine the specific cause of their illness.
Regarding FDA's standards for bacteria in bottled water, those standards should be made more stringent to be consistent with FDA's tougher standards for bacteria in tap water. However, Bayer’s assertion about FDA’s weak bottled water standards is irrelevant to the issue of antibiotic resistance and it does not excuse Bayer from criticism for jeopardizing public health by keeping Baytril on the market.
- Bayer assertion: “Baytril is used for therapeutic purposes only and in less than 1 percent of U.S. broiler flocks. It is used only when prescribed by a veterinarian for specific life-threatening poultry diseases and only when disease is severe enough to cause high mortality in poultry. Federal law prohibits the extra-label use of this drug in food-producing animals. Baytril is never used in the feed of animals, and it is not a growth promoter.”
Response: Even if only 0.5 percent of the more than 8 billion broiler chickens processed annually in the United States are treated with Baytril each year, that’s 40 million treated chickens! In 1999, industry estimated that around 38,000 pounds of Baytril were given to poultry. Although Baytril is only prescribed by veterinarians for treatment of illness, treatment is not limited to individual sick birds. Rather, Baytril is administered to an entire poultry flock (which may consist of more than 30,000 birds) – via the facility’s drinking water system – even if only a portion of the flock is sick. This treatment of healthy as well as sick birds, each receiving levels of antibiotic that vary with their water consumption, is a recipe for the proliferation of antibiotic-resistant Campylobacter.
- Bayer assertion: “The safety and wholesomeness of the nation’s food is dependent upon the availability of effective therapeutics, including antimicrobials [antibiotics]. Baytril is the only effective antimicrobial available for some of the most serious bacterial diseases in poultry.”
Response: The assertion that “Baytril is the only effective antimicrobial available for some of the most serious bacterial diseases in poultry” is conspicuously at odds with statements by six of the top 20 U.S. poultry producers, including Tyson Foods (#1), Gold Kist (#2), ConAgra Poultry (#4), Perdue Farms (#5), Foster Farms (#9), and Claxton (#19), that they no longer use fluoroquinolones in chickens produced for human consumption.
- Bayer assertion: “A recent assessment of CVM’s position by the European Agency for the Evaluation of Medicinal Products (the European equivalent of the FDA) supports Bayer’s conclusions that the use of Baytril in poultry poses no public health threat.”
Response: The assessment in question was actually prepared by European Agency for the Evaluation of Medicinal Products’ Committee on Veterinary Medicinal Products, which is comprised of veterinarians and animal scientists rather than medical or public-health experts. By contrast, U.S. health care professionals are very concerned about the threat to public health from the use of Baytril in poultry. More than 180 U.S. health care professionals and organizations, including the American Medical Association and the American Public Health Association, have written Bayer Corporation asking the company to withdraw Baytril.
Moreover, Bayer misrepresents EMEA's assessment, which agrees with most of FDA’s analysis concerning the use of fluoroquinolones in chickens. EMEA's assessment refutes many of Bayer’s claims, including items (2) and (3) above. However, EMEA's assessment downplays the threat of fluoroquinolone-resistant Campylobacter to humans, stating that most Campylobacter infections in humans do not require antibiotic treatment and that alternative antibiotics are available. This portion of EMEA's conclusions is partially contradicted later in EMEA assessment, which notes that early treatment with fluoroquinolones can be critical to prevent complications in patients at particular risk for severe Campylobacter infections. These patients include senior citizens as well as people with less-effective immune systems because of chemotherapy, HIV/AIDS, transplant-related immunosuppression, or other factors.
- Bayer assertion: “Baytril was licensed by CVM [the FDA Center for Veterinary Medicine] after thorough review and is regarded by as an essential drug by veterinarians. Bayer takes seriously its responsibility to base any and all decisions regarding Baytril on solid scientific evidence. Scientific data clearly show that the judicious use of Baytril on the farm, under the supervision of veterinarians, contributes to the wholesomeness of our food while preserving the effectiveness of fluoroquinolones as powerful antimicrobial [antibiotic] agents…Withdrawing Baytril for poultry will increase the likelihood of food-borne illness.”
Response: In October 2000, FDA initiated proceedings to revoke its prior approval of fluoroquinolones for poultry, based on scientific data the agency received after granting the approval in 1995. (It is worth noting that the Centers for Disease Control strongly opposed the approval in 1995, and strongly supports the withdrawal.) We know of no data showing that the use of Baytril in poultry contributes to the wholesomeness of foods. Baytril is used to treat respiratory diseases in poultry, not Campylobacter – Campylobacter does not make poultry sick. However, as discussed above, the use of Baytril in poultry is compromising the effectiveness of Cipro and other fluoroquinolones to treat human illness.
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