The US Food and Drug Administration (FDA) on Monday issued a lengthy-and rare-statement fighting back against a report issued by the Environmental Working, an advocacy group focused in part on antibiotic resistance and the judicious use of antibiotics, saying the group's analysis was built on an oversimplification of publicly available data.
Various news reports in recent years have highlighted the role of the overuse of antibiotics in food-producing animals as one of the most prominent sources of antibiotic resistance. While FDA's authority to require comprehensive data reporting on the use of antibiotics is relatively limited, it nevertheless has various authorities to require veterinary drug manufacturers to report basic information.
That information is collected by FDA's Center for Veterinary Medicine (CVM), which enters it into a database known as the National Antimicrobial Resistance Monitoring System (NARMS), a joint project of FDA, the Centers for Disease Controls and Prevention (CDC), the US Department of Agriculture (USDA) and the Department of Health and Human Services (DHHS).
That program has been making strides in recent years toward developing more robust and complete data-collecting methodologies. A May 2012 report issued by FDA, for example, said the agency wanted to collect data from a greater representation of US geographical locations, develop strategies to test animals for resistance before they are slaughtered and generate methods to better assess national estimates of resistance.
In addition, FDA said it wants to revamp the way it acquires, analyzes and reports data obtained from its various sources, in part by creating an "integrated database" that would pool data from multiple sources and help the agency publish and annual surveillance report.
More recently, FDA said it wants to reassess the information collected from industry regarding veterinary antimicrobial drug sales, distribution and resistance data, and specifically for drugs approved and labeled for more than one food-producing animal species.
"Currently, sponsors of antimicrobial drugs that are approved and labeled for multiple animal species, including both food-producing and non-food-producing animals, do not report sales and distribution information for each individual animal species," FDA explained in a Federal Register posting. "Only total product sales information is reported."
"Such information would further enhance FDA's ongoing activities related to antimicrobial resistance and is consistent with the recommendations in guidance recently issued by this Agency addressing the judicious use of medically important antimicrobial drugs in food-producing animals," FDA added.
FDA's last point-that the data is presented in aggregate format-is the crux of their pushback against the Environmental Working Group's new report, Superbugs Invade American Supermarkets.
In it, the group says its analysis found that antibiotic-resistant bacteria had been found in 81% of ground turkey, 69% of pork chops, 55% of ground beef and 39% of chicken (breasts, wings and thighs).
Those data were based on NARMS' annual publication, it said, and the report goes on to cite a number of other troubling findings-high rates of superbug versions of salmonella in recalled chicken and turkey samples, campylobacter jejuni superbugs in raw chicken, and Yersinia enterocolitica in the majority of raw pork.
The report received a considerable amount of media coverage, including on CNN.
'Simplistic and Alarmist'
The problem, FDA said in a rare statement, is that the Environmental Working Group's assumptions are based off a "simplistic" reading of the data.
"While FDA is always concerned when we see antimicrobial resistance, we believe the EWG report oversimplifies the NARMS data and provides misleading conclusions," FDA wrote. "We do not believe that EWG fully considered important factors that put these results in context."
Those problems include the report's inclusion of some pathogens that are not foodborne, the report's failure to note which drugs the bacteria are resistant to, whether resistance to a particular drug represents a risk to public health, whether options still exist to combat the bacteria in question, and failure to place the data in any sort of historical context.
"We believe that it is inaccurate and alarmist to define bacteria resistant to one, or even a few, antimicrobials as 'superbugs' if these same bacteria are still treatable by other commonly used antibiotics," FDA explained. "This is especially misleading when speaking of bacteria that do not cause foodborne disease and have natural resistances, such as Enterococcus."
FDA's Own Analysis
FDA's own analysis of the data on the same points found similar, if considerably more nuanced conclusions, it said.
- 2011 data showed no fluoroquinolone resistance in Salmonella from any source
- Trimethoprim-sulfonamide resistance remains low (0% to 3.7%).
- Fluoroquinolone resistance in Campylobacter has remained essentially unchanged since 2005.
- Macrolide antibiotic resistance in retail chicken isolates remains low (0.5%).
- Multidrug resistance is rare in Campylobacter.
- Gentamicin resistance in Campylobacter coli markedly increased from 0.7% in 2007 to 18.1% in 2011.
- Resistance to third-generation cephalosporins has increased in Salmonella from chicken (10 to 33.5%) and turkey (8.1 to 22.4%) meats when comparing 2002 and 2011 percentages.
"Antimicrobial resistance is a serious and challenging issue," FDA concluded. "FDA welcomes all contributions in helping to understand and address the challenge of antibiotic resistance. However, it is very important to look at the NARMS data in the proper context, with a good understanding of the microbiology, epidemiology and genetics of antibiotic-resistant foodborne pathogens and their clinical management. "
FDA: FDA Cautions in Interpretation of Antimicrobial Resistance Data
EWG: Superbug Report