Citing concerns about the growing threat of bacterial infections that are resistant to antibiotics, the U.S. Food and Drug Administration this month ordered farmers and ranchers to curb the use of cephalosporins, a common class of antibiotics used to treat several human illnesses.
This was a move in the right direction, but not by much. U.S. farms feed their animals about 29 million pounds of antibiotics annually, according to FDA estimates. Cephalosporins accounted for about 54,000 pounds of that total in 2010.
The vast majority of these agricultural antibiotics are given to animals that are healthy, because a constant stream of low-dose antibiotics helps prevent illnesses and infections. As a notable side-benefit for meat and poultry producers, these drugs also make animals grow faster.
But, doctors and microbiologists are alarmed about the recent increase in antibiotic-resistant bacteria, such as MRSA, drug-resistant tuberculosis and new strains of E. coli and salmonella. Groups including the American Medical Association, the American Public Health Association and the World Health Organization believe that this regular use of antibiotics on farm animals is largely responsible. They argue that when colonies of bacteria are constantly exposed to low doses of antibiotics, the weakest bacteria are killed off, leaving only the stronger survivors to multiply. After several successive generations, the result is new strains of bacteria that are completely unaffected by antibiotics.
Since this page last addressed this topic two years ago, very little has changed. The use of sub-therapeutic antibiotics on healthy animals is still the norm in conventional agriculture, and meat and poultry groups still flatly deny that the practice could be contributing to any broader problem related to human health.
But, it is becoming more difficult to argue that these superbugs are not a problem on the farm. Last year alone, outbreaks involving three separate drug-resistant salmonella strains sickened almost 350 people. All three strains were ultimately traced to meat and poultry products.
The FDA currently says that it is committed to promoting voluntary reform of these practices. If the agency is unsure of the link between agricultural antibiotics and drug-resistant bacteria, then it needs to conduct more definitive research. If it believes that there is a link, then limiting cephalosporins and asking producers to regulate themselves is clearly an insufficient response.