Two weeks after stealthily announcing that it planned to withdraw a 34-year old petition to impose real restrictions on the use of antibiotics in livestock feed, the U.S. Food and Drug Administration (FDA) issued a statement on Tuesday revealing it has prohibited certain uses of a class of antibiotics known as cephalosporin in animals intended for human consumption.

Citing its concern that the overuse of cephalosporins to treat farm animals could lead to the development of drug-resistant pathogens that could be passed on to humans, the FDA said in a statement that use of the antibiotic at unapproved dose levels or for disease prevention in cattle, swine, chickens and turkeys will be banned effective April 5.

Cephalosporins are commonly used in humans to treat pneumonia as well as to treat skin and soft tissue infections. In addition, they are used in the treatment of pelvic inflammatory disease, diabetic foot infections, and urinary tract infections. If cephalosporins are not effective in treating these diseases, doctors may have to use drugs that are not as effective or that have greater side effects, the FDA said in the statement.

While the restriction has been praised by organizations such as the Pew Campaign on Human Health and Industrial Farms and the Alliance for the Prudent Use of Antibiotics as an important first step toward addressing the adverse human health consequences resulting from the overuse of antibiotics in farm animals, it is ultimately a limited move in the grand scheme of the issue.

In fact, the use of cephalosporins to treat food-producing animals has been declining in recent years in favor of alternate classes of antibiotics. In 2010, the FDA reported cephalosporins constituted less than 0.25 percent of antibiotic sales for farm animals domestically. The industry purchased about 91,000 pounds of the drug in 2010, considerably less than any other antibiotic, as well as a 41 percent decrease from 2009.

Antibiotics Use

The overall use of antibiotics -- often included into livestock feed in order to encourage animal growth and ward off bacteria that could result from unsanitary living conditions -- has remained steady. The FDA numbers indicate cephalosporins are being phased out in favor of ionophores, penicillins and tetracyclines, the latter of which is by far the most popular, with more than 12 million pounds sold in 2010. Sales of penicillins increased 43 percent between 2009 and 2010, while tetracycline sales rose 21 percent.

Interestingly, penicillin and tetracyclines are the very class of drugs the FDA recommended imposing restrictions back in 1977. In the petitions the agency submitted that year calling for their regulation, the FDA cited scientific research indicating that animals that have received either subtherapeutic and/or therapeutic amounts of antibiotic and sulfonamide drugs in feeds may serve as a reservoir of antibiotic resistant pathogens and non-pathogens. These reservoirs of pathogens can produce human infections.

The FDA's petition to regulate those classes of antibiotics languished for more than three decades, until the agency posted an obscure announcement in the Federal Register on Dec. 22 stating it decided to revoke its petition in favor of encouraging voluntary reform and regulation within the industry, essentially reiterating the status quo.

Meanwhile, scientists report antibiotic use in animal agriculture has continued to grow. Approximately 70 to 80 percent of all antibacterial drugs in the U.S. are sold for use in livestock animals, a reality that U.S. Rep. Louise Slaughter, D-N.Y., the author of the Preservation of Antibiotics for Medical Treat Act, said is contributing to the rise in deadly antibiotic-resistant bacteria.

This irresponsible use represents a serious threat to public health in America. Just last year, 60,000 Americans died in hospitals as a result of antibiotic resistant infections, Slaughter said in a statement.

In May 2011, the Natural Resources Defense Council (NRDC), along with a coalition of medical and public health organizations, filed a lawsuit against the FDA alleging that the agency failed to meet its legal responsibility to address the escalating health threat posed by the escalation of antibiotic-resistant bacteria in farm animals. Avinash Kar, a staff attorney with the NRDC, suggests the timing of the newest FDA announcement is an attempt to placate the general public from the broader issue by implementing what amounts to be a token regulation.

Not only are penicillins the most widely used class of antibiotics in human medicine, their use in livestock can also cause resistance to cephalosporins (just as cephalosporin use can cause resistance to penicillins), Kar wrote on Thursday, explaining that imposing stricter regulations on cephalosporins alone will barely make a dent in preventing the development of drug-resistant pathogens in farm animals that can then be passed on to humans.