The U.S. Food and Drug Administration allowed dozens of antibiotics used in animal feed to stay on the market despite findings by its own researchers that the drugs will likely expose people to antibiotic-resistant infections, according to a report released Monday by an environmental advocacy group.
The FDA reviewed 30 different types of antibiotics that are put into livestock feed and found that 18 of them pose a “high risk” of exposing humans to antibiotic-resistant bacteria through the food supply, the Natural Resources Defense Council said in a report about the FDA’s findings.
The manufacturers of the other 12 drugs didn’t submit enough information to the FDA in order to determine whether they could be safely used in animals without harming humans, but the FDA did not withdraw its approval of any of the antibiotics following its review, according to the NRDC.
“To our knowledge, FDA has taken no action since the reviews to revoke approvals for any of these antibiotic feed additives,” the NRDC’s report said.
“I was shocked,” Carmen Cordova, a microbiologist for the NRDC and lead author of the report, told Al Jazeera.
“These are their very own findings,” she said. “This is still a question we have as to why there’s been no action, essentially, for 40 years. What we think is that they simply bow to industry.”
The NRDC accessed the FDA’s review of the drugs, which the agency conducted from 2001 to 2010, through a Freedom of Information Act request and the settlement of a subsequent lawsuit NRDC filed against the FDA.
The FDA’s documents, which were partially reviewed by Al Jazeera, also found that 26 out of the 30 antibiotics didn’t meet the safety standards laid out by the FDA in 1973 requiring drug manufacturers to submit evidence that their drugs didn’t create antibiotic resistance that could endanger human health.
The FDA’s review did not clearly indicate how many of the drugs continue to be sold today, but the NRDC said it found evidence that at least nine of the antibiotics continue to be marketed as additives to animal feed.
Some of the drugs in the FDA's review have been used since the 1950s, the NRDC said, and while the FDA sent letters to some of the drug companies asking for more safety information, it didn’t take further action and none of the companies reportedly submitted extra safety studies.
The World Health Organization, the U.S. Centers for Disease Control and other public health organizations have warned in recent years that widespread use of antibiotics could create a dangerous rise in drug-resistant strains of tuberculosis, gonorrhea, staph infections and other so-called “super bugs.”
At least 2 million people in the U.S. develop serious bacterial infections that are resistant to at least one type of antibiotic annually, and more than 23,000 people die each year from antibiotic-resistant infections, according to the CDC.
The FDA said in an email statement to Al Jazeera that “antimicrobial resistance is a complex issue with many causes, and uses of antimicrobial drugs in both humans and animals contribute to the development of antimicrobial resistance.”
The agency recently began to implement its new strategy “to phase out the use of all medically important antimicrobials, including penicillins and tetracyclines, for production purposes such as growth enhancement,” the FDA wrote, referring to its December 2013 policy asking drug companies to voluntarily stop labeling the drugs as acceptable to use in animals for purposes such as disease prevention or animal growth.
The FDA told Al Jazeera that two drug companies — Zoetis and Elanco — had already signed on to its voluntary program, and that it was “confident that this strategy will be fully implemented over the next three years. Once implementation of the strategy is complete, it will be illegal to use these drugs for non-therapeutic uses.”
It added, “We note that our strategy also does not limit our authority to take future regulatory action.”
In 2012, a federal district court ruled (PDF) that the FDA must start the process of withdrawing approval for tetracyclines and penicillins in animals for what’s known as “non-therapeutic use,” meaning for any purpose beyond treating an existing illness. The FDA is appealing the decision.
Those non-therapeutic purposes include the prevention of illness, which is necessary for some livestock producers in the U.S. to prevent animals from getting sick in sometimes crowded or unsanitary conditions. Another use is to make the animals grow faster.
The European Union in 2006 banned the practice of giving antibiotics to livestock for the purposes of promoting growth, and while Sen. Dianne Feinstein (D-Calif.) introduced similar legislation in the U.S. last year, Congress has yet not passed it.
The FDA in 1977 proposed withdrawing its approval of antibiotics after finding that feeding low doses of drugs to animals that are also important for treating human illnesses can promote drug-resistant infections, but it never took any regulatory action.
The agency did not answer Al Jazeera’s question about why it did not withdraw the approval of antibiotics as feed additives if they did not meet the agency’s safety guidelines.
"I think the FDA has an obligation to go ahead and withdraw the drugs and quit delaying, and that’s the sad part, is that they constantly fail to do so,” Steve Roach, the food safety program director at the advocacy group Food Animal Concerns Trust, told Al Jazeera.
“Why is the FDA so afraid of taking legal action? Why don’t they just move forward with the withdrawals and ask the companies not to voluntarily challenge them in court?” he said. “Basically, what they’re saying is, ‘Our job is too hard, so we’re not doing this.’”