A few hours before Washington, D.C.’s press corps left town for the long July 4 weekend, the U.S. Food and Drug Administration (FDA)—specifically its Center for Veterinary Medicine—released "Antimicrobial Use and Resistance in Animal Agriculture in the United States". It is the FDA’s first summary report looking at the critical nexus of antibiotic use and antibiotic resistance in food-producing animals (“livestock”).
Disappointingly, the report confirms our long-standing impression that FDA’s response to the antibiotic resistance crisis is deeply flawed. Especially absent are critically important public health elements. These are elements needed to hold the FDA accountable for delivering real and measurable reductions in overall levels of antibiotic use and overuse.
Public health experts, along with local, federal, and global public health agencies, agree that antibiotic use and overuse are the single-most-important factors driving the development of antibiotic resistance and its global spread. The increase in infections caused by antibiotic-resistant bacteria, sometimes called “superbugs,” is scary. By latest estimates, these superbugs directly cause about 1.3 million deaths each year worldwide, and are associated with—i.e., a less direct contributor to—nearly three times that number of deaths as well.
We describe three examples where FDA’s approach to antibiotic use and antibiotic resistance in livestock settings falls short. Following each of them is a concise description of desperately needed changes to FDA policies or actions—changes that are essential in order to fully protect the public from the superbug threat.
1) FDA’s language problem
Nowhere in its report does FDA acknowledge the robust science—and scientific consensus—that antibiotic use and overuse, wherever they occur, are the most important drivers of the antibiotic resistance threat. In fact, nearly two-thirds of all medically important antibiotics in the United States are sold for livestock, not for human medicine. Globally, that figure is even higher, around 80 percent.
The FDA instead downplays the public health importance of antibiotic use and overuse in livestock production. On page 8 of the report, for example, it states “[A]ntimicrobial use is one driver among others [emphasis added] in the development of resistance….” Nowhere does the report use the terms antibiotic “overuse,” “misuse,” “inappropriate” use, or “unnecessary” use in reference to animal agriculture.
The public health need
Language is important. The FDA’s choice of language demonstrates its fundamental lack of public health focus or understanding. “Antibiotic resistance is rising to dangerously high levels in all parts of the world,” says the World Health Organization, and it’s driven by levels of antibiotic use and overuse, including in livestock production. The FDA should say as much.
2) FDA’s problem—Actions would speak even louder than words
The U.S Government Accountability Office urged the FDA in 2004, 2011, and 2017 to begin tracking antibiotic use in livestock at the farm level. To date, however, the FDA has never done so. The agency has put far more time and resources toward the goal of “supporting” individuals (namely, veterinarians and livestock producers) to practice antibiotic stewardship in livestock production.
By now, the FDA also should have embraced the role of collecting and reporting the evidence needed to show whether its antibiotic stewardship efforts have demonstrably improved public health. In its latest report, however, the most FDA can promise is to “continue to explore new strategies to collect and analyze antimicrobial drug use data in food-producing animals.” But when?
The public health need
Tracking antibiotic use and spotting overuse are recognized as public health imperatives, since they drive the occurrence and spread of resistance. In recent years, the CDC has committed itself to doing a better job at tracking antibiotic use in human medicine, where in some settings, the level of overuse may approach 50 percent.
To protect public health, the FDA should aspire to do the same. Regular surveillance (and not very occasional monitoring) of antibiotic use at the farm level is essential for FDA to be able to spot and respond to patterns of antibiotic overuse. The data generated would also be the best and perhaps the only means for FDA to demonstrate that its antibiotic stewardship campaign has worked—or not.
If Congress expects the FDA to fully protect public health, then it also must fund and hold the FDA accountable for building surveillance systems to regularly track and report antibiotic use at the farm level. Without those systems, the United States, as one of the world’s largest consumers of antibiotics, cannot fully do its part to slow the spread of resistance.
3) FDA’s problem—Failing to use all data that pertain to livestock antibiotic use
The only data the FDA routinely collects pertaining to antibiotic use in livestock are sales data. It now has 12 years’ worth of such data, encompassing annual sales for all food animal production from 2009 to 2020. It is worth noting that FDA only started asking pharmaceutical companies to report antibiotic sales by individual animal species beginning in 2016.
In 2017, the FDA issued a proposal for calculating and then reporting sales data on a “weight-adjusted” basis. FDA has explained the purpose in doing weight adjustment of raw sales data is to “provide insight into broad shifts in the amounts of antimicrobials sold for use in food-producing animals and to allow for a more nuanced view of how sales increase or decrease over time…” (page 34 of the report), a goal NRDC very much supports. Yet the FDA's most recent report is the first instance where it actually did weight adjustments to sales data, although only for sales in 2016 through 2019. FDA vows to continue weight-adjusting raw sales in subsequent years, as those data are published. FDA has not committed, however, to reporting weight-adjusted sales every December, at the same time it releases the annual summary of raw (unadjusted) sales for the previous year.
In deciding to weight-adjust raw sales only beginning in 2016, the FDA made a de facto decision not to weight-adjust the already-released sales for 2009 to 2015. That decision negatively impacts public health, and bears closer scrutiny. By weight-adjusting sales over only four years rather than 12 years, the FDA ensures the scientific basis for the agency to draw public health conclusions is weaker than it could be. If the FDA instead had completed weight-adjustment of sales over 12 years, it would now have a greater degree of confidence that observed trends in sales over that time were reflective of actual changes in antibiotic use at the farm level. Additionally, we know from previous FDA reporting that raw U.S. (unadjusted) antibiotic sales rose by 2 million kilograms from 2009 to 2015, when they peaked. By starting its weight-adjustment of sales in 2016, just after the peak, the FDA has created -- unnecessarily -- a misleading impression of how much sales decline has occurred since the agency publicly released its 2012 guidance for the livestock industry to voluntarily adopt better antibiotic stewardship in food animal production.
The public health need
The European Medicines Agency (EMA), the FDA’s European counterpart, has been reporting livestock antibiotic sales, side by side, on both a raw and weight-adjusted basis since 2011. Those European data are now available for every year from 2009 to 2020. On that basis, the EMA has gained “insight into broad shifts” in the amounts of antibiotics "consumed" by livestock production over a much longer stretch of time than the FDA. Informed by 12 rather than just four years’ worth of data, the EMA’s reporting arguably delivers more insight and public health value than does the FDA’s reporting.
Besides the EMA, other government agencies and independent researchers have long endorsed the tracking of changes in livestock antibiotic sales over time, on a weight-adjusted basis. They emphasize that there is a public heath importance to do so when farm-level data on antibiotic use are not being regularly collected and reported. The latter, of course, is the case in the United States.
FDA has the opportunity to do more, and it should do more weight adjustment of sales data. Specifically, FDA should take immediate action to weight-adjust all of its raw data on sales of medically important antibiotics for use across the entirety of food animal production dating back to 2009, and not merely the post-2015 data. Doing so would give public health experts the ability to compare trends in weight-adjusted sales for livestock production over an identical time period in the United States and across Europe as an entire region, as well as for up to 31 individual European countries that report national livestock antibiotic sales data.
Over the past decade, the FDA has spent more effort on a campaign to support individual antibiotic stewardship than in building surveillance systems to track and regularly report data pertaining to antibiotic use and overuse in livestock production. Both processes provide some benefit to better understanding antibiotic resistance in livestock settings. Only the latter, however, is a public health function which, if done well, would (a) provide the public benefit of identifying patterns of antibiotic overuse; and in doing so, (b) also provide the means for taking government action to reduce those avoidable uses of antibiotics, thereby slowing the spread of resistance.
The FDA still does no regular collection of data on antibiotic use and overuse. As a result, it lacks the means answer a simple, but critically important public health question: Has antibiotic stewardship on U.S livestock farms improved since 2009, or not?
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