Studies have tied the misuse of antibiotics on factory farms to the rise of resistance, but the FDA keeps delaying action. Is it too late now?
Last week, a U.S. district court judge ordered the Food and Drug Administration (FDA) to move forward on ending the use of several antibiotics in food animals except to treat disease. In doing so, the court sent a clear message to the agency: do your job.
Although hundreds of peer-reviewed papers from decades of scientific research have linked the misuse of antibiotics on farms to the rise of antibiotic resistance that now threatens the public health, the FDA has pursued a strategy of "voluntary reform," politely asking drug companies to change their ways but not requiring them to do so. Last Thursday, the judge rebuked the FDA for its passive approach and demanded that the agency follow through on banning uses of drugs by industrial food animal producers that even its own experts no longer consider safe.
THE SCIENCE IS CLEAR
The vast majority of antibiotics in this country -- about 80 percent -- are sold for use in food animal production, not to treat humans. The vast majority of animals that receive these drugs are not sick, and the doses they receive would be too low to successfully treat bacterial infections if they were. Rather, low doses of antibiotics are fed to healthy animals throughout their lives to speed their growth and to reduce infections in the overcrowded and unsanitary conditions commonly found at the industrial operations that produce these animals.
Using antibiotics this way continuously exposes bacteria to low doses of these drugs, providing an ideal environment for the emergence of antibiotic-resistant bacteria that can infect humans on farms, in the environment, and in the food we eat. For this reason, physicians and scientists have long sought restrictions on the agricultural use of antibiotics.
Likewise, the World Health Organization (WHO) has highlighted the misuse of antibiotics in food animal production when warning of a "post-antibiotic era" in which drugs are no longer effective and currently manageable infections, left untreated, turn deadly.
DECADES OF INACTION
In 1977, the FDA determined that using penicillins and tetracyclines to make animals grow faster was no longer "shown to be safe," as research had linked such uses to the development of antibiotic resistance. The agency began the process of withdrawing their approvals, publishing what it calls "notices of opportunity for a hearing."
Such notices, the first step in any withdrawal process, set out the rationale for the withdrawal and allow companies that manufacture the drugs to request an administrative hearing to contest the FDA's decision. At these hearings, companies bear the burden of proof and must show that the uses in question are safe. If they cannot, the agency withdraws its approval.
The FDA never held a hearing in 1977, however. Under pressure from Congress, the agency backed down, leaving the approvals in place. Although the FDA did not rescind the notices, in theory leaving the matter open for future consideration, the agency took no further action to restrict either drug class for the next 34 years.
Frustrated by the FDA's lethargy, consumer advocacy groups petitioned the agency in 1999 and again in 2005 to complete the process it had begun three decades earlier. The FDA ignored both petitions until the groups sued for action last year. The agency denied both petitions in response. The FDA then withdrew the notices on penicillins and tetracyclines, claiming it would pursue "other regulatory strategies" to address antibiotic resistance instead.
These "regulatory strategies" have been entirely voluntary. In 2010, the agency released a draft guidance document that described how antibiotics should -- and should not -- be used on farms to minimize selection for antibiotic resistance. Notably, the FDA wrote that using antibiotics for growth promotion "is not in the interest of protecting and promoting the public health." The agency nevertheless described using antibiotics to prevent infections as "necessary and judicious." That is, the FDA endorsed feeding low doses of antibiotics to food animals throughout their lives to prevent infections, if not to promote growth. This practice has time and again been shown to select for antibiotic resistance.
When it withdrew the notices on penicillins and tetracyclines, the FDA insisted that drug companies would voluntarily implement the principles outlined in the guidance document, making unnecessary the very regulations the agency once sought. The Animal Health Institute, an industry lobby group, has said the same. Because the guidance document endorses continued long-term use of low doses of antibiotics, ostensibly to prevent infections, the industry's cooperation is not surprising.
The voluntary approach did not fly with the court. Under the law, it said, the FDA cannot find that an approved use of a drug is no longer safe and then refuse to withdraw its approval. Because the agency made such a determination in 1977, the court said, it must withdraw its approval now, unless drug companies can prove at an administrative hearing that the drugs are actually safe.
The FDA will now need to re-issue the notices of opportunity for a hearing and begin the withdrawal process anew, assuming the agency does not appeal the ruling and drag out the litigation for many more months.
If the decision survives on appeal, pharmaceutical companies appear poised to drag out the process for years, contesting the withdrawal of each approval of each drug at a separate hearing. These hearings typically involve thousands of pages of written evidence and many hours of expert testimony. With untold quantities of money -- and armies of lawyers and paid scientists -- the drug industry could keep misusing antibiotics while fighting the withdrawals. The advocacy groups that sued the agency have asked the judge to set a timeline that ensures prompt action.
THE ROAD NOT TAKEN (YET)
The full impact of the decision remains to be seen. An important question is, Has the agency found that any other approved uses of antibiotics are no longer "shown to be safe," or might it do so if confronted with the scientific evidence that they are not? If the answer is yes, groups advocating sound regulations on antibiotic use will have an opening to force the withdrawal of other antibiotics as well.
We can expect a wave of lawsuits and legal petitions in the coming years that make a case for such findings and demand action by the FDA. Because the agency has already said that using antibiotics for growth promotion "is not in the interest of protecting or promoting the public health," one hopes that the FDA will accept the scientific consensus that these uses are unsafe and withdraw all current approvals of antibiotic growth promoters.
The media's coverage of the decision has focused on the use of antibiotics for growth promotion. While ending these uses would be an important step, it would not be sufficient to end the misuse of antibiotics in industrial food animal production. As long as low doses of antibiotics may be continuously fed to food animals to prevent disease, the industrial operations that produce the majority of food animals in this country will continue to serve as giant incubators for antibiotic-resistant bacteria.
It is unclear whether the FDA still considers the use of antibiotics to prevent disease safe. The agency has acknowledged that feeding antibiotics to entire herds or flocks, for disease prevention and other purposes, "poses a qualitatively higher risk to public health" than treating individual sick animals. the FDA has nevertheless termed the preventive use of antibiotics "necessary and judicious."
The use of antibiotics for disease prevention is only necessary because companies have chosen to raise food animals using methods that make them especially susceptible to infectious diseases. If we improved the diets and living conditions of the animals, we could prevent disease without compromising the effectiveness of antibiotics and putting the health of the public at risk. This is how Denmark ended the misuse of antibiotics in 2000 -- over strenuous objections from the Danish swine industry -- and remained the world's top exporter of pork.
How we use antibiotics, in animals as in humans, will determine the rate at which infections become resistant to antibiotic treatment. If we take steps now to ensure responsible use of these drugs -- including a ban on their use for growth promotion and disease prevention at industrial farms -- we can slow the rise of resistance. The recent court decision offers hope that this is possible. We now must push the FDA to comply with the decision and to extend the logic of the ruling to other antibiotics. We do not have much time.