A Critical Antibiotic Is Being Used on Livestock, and Going Untracked

It has become clear in recent years that the growth of antibiotic resistance poses a serious threat to human health, and that the use of antibiotics on food animals is a major piece of the problem.

Good tracking of livestock antibiotic use is important for understanding the magnitude of the  risk. The passage of the Animal Drug User Fee Amendments of 2008, which required reporting on livestock antibiotic sales for the first time in the United States, was a modest step forward. Because of the law, we know the quantity of antibiotics sold for use on animals in the United States over the last four years.

Although current reporting is still far from adequate, we can glean some useful information from the FDA reports. For example, we now know that the antibiotic class cephalosporin –critically important for human health, and vulnerable to being rendered ineffective by the development of resistant bacteria – has been used more and more in livestock in recent years.

Cephalosporin use on livestock is on the rise. Source: FDA (PDF)

Yet we are still unable to track the sales figures for one of the antibiotic classes most critical for human health due to a loophole in the 2008 law. Fluoroquinolones are an antibiotic class critical for treating bacterial infections, and are used to treat a number of deadly diseases that are in the midst of developing resistance. Fluoroquinolones are also one of just two classes of antibiotics for which the FDA has prohibited extralabel use (the other class is cephalosporins). In addition, there is reason to believe that fluoroquinolones are being used in violation of the FDA’s ban on extralabel use, potentially in a way that encourages further resistance.

The 2008 law contained a provision that antibiotic classes for which fewer than three companies sponsor applications for use do not need sales data reported. Because fluoroquinolone antibiotics fall into this category, we can only see fluoroquinolone sales data grouped together with other “Not Independently Reported” antibiotics, denying us potentially enlightening information.

The dearth of information available on fluoroquinolone use on livestock is illustrative of the woeful state of reporting and tracking of all antibiotic use on animals. Antibiotic resistance poses a serious threat to human health, and the public needs to know if, and to what extent, important antibiotics are being misused.