A salmonella outbreak traced to California chicken processing plants recently prompted Rep. Louise Slaughter, D-N.Y., to raise a pet issue on MSNBC: antibiotic-resistant bacteria.
The federal shutdown was limiting government’s ability to track infection, she said. But then she pointed to a deeper issue: "the overuse and ruination of antibiotics."
An advocate for tougher requirements for farm use of such drugs, Slaughter told host Joy-Ann Reid that she’s been "trying to save antibiotics for persons — for human beings."
"Eighty percent of the antibiotics in this country are fed to livestock every single day, and it's creating a terrible problem of resistant bacteria," she said.
Eighty percent is an awfully big number, and we were curious: Do livestock consume the bulk of the nation’s antimicrobial drugs?
It’s an important question, because according to the U.S. Centers for Disease Control and Prevention, wide use of antibiotics in food-producing animals "contributes to the emergence of antibiotic-resistant bacteria in food-producing animals."
Emergence of resistant bacteria means if you get infected with bacteria from the food you eat, it might be harder to fight that infection with antibiotics. Drug resistance may be contributing to higher hospitalization rates in the recent salmonella outbreak, for example, the Los Angeles Times reported.
Here’s how it works, according to the CDC: Ranchers give animals antibiotics, which kills off or suppresses susceptible bacteria, but allows antibiotic-resistant bacteria to thrive. Those resistant bacteria may be transmitted to people through the food supply, such as by eating undercooked salmonella-tainted chicken. Since the bacteria are resistant to some antibiotics, the infections may be harder to fight, causing "adverse human health consequences."
So CDC "encourages and supports efforts to minimize inappropriate use of antibiotics in humans and animals."
You’re probably aware of this effort in humans — it’s why doctors are discouraged from giving their patients antibiotics to treat nonbacterial infections such as cold and flu. Widespread use of antibiotics when they’re not required helps bacteria develop defenses to the drugs in a sort of microscopic arms race.
It’s also the reason the U.S. Food and Drug Administration has asked farmers to phase out certain antibiotics important to human medicine when used merely to promote growth in animals. (The industry says this accounts for a small amount of antibiotic use. The FDA says it’s hard to say.)
So, back to the 80 percent number. It turns out it has been a popular talking point since 2010 among those who advocate for restricting use of antibiotics on farms. That’s the year the FDA released newly required data on sales of antibiotics by manufacturers for food-producing animals. The FDA didn’t release sales information on antibiotics for human use, but pointed to national projections from IMS Health, a Connecticut company that compiles proprietary health data.
The numbers let folks compare the millions of kilograms of drugs sold by manufacturers for use by food-producing animals (13.1 million kilograms) in 2009 with those sold for use by people (3.3 million kilograms). The 13.1 million kilograms of antibiotics sold for animals was 80 percent of the total amount of drugs sold for both humans and animals, which was 16.4 million kilograms.
We should note this comparison doesn’t account for all antibiotics sold in the United States. For example, it doesn’t count antibiotics sold for household pets.
A researcher with the Johns Hopkins School of Public Health’s Center for a Livable Future first did the math for a 2010 blog post that’s been widely cited. (The most recent reports reveal a similar proportion, as calculated by the Pew Campaign on Human Health and Industrial Farming.)
But while it offers a series of caveats about drawing "definite conclusions" from "direct comparisons" about the drug sales data — such as differences in dosages between different drugs and in the sizes of human and animal populations — it confirms both sets of sales data essentially measure the same thing.
Both show the volume of antibacterial drugs, by weight, being sold to various outlets from the manufacturer. So, while they don’t offer a direct estimate of human or animal use, they do offer a comparison of sales by manufacturers for both groups.
In 2011, the FDA provided the IMS Health sales estimates directly to Slaughter, describing the sales numbers as "a surrogate for human use to compare to antibacterial drug use in animals."
We should note that about a third of the antibiotics used in food-producing animals are ionophores, a type not used in humans. (The agriculture industry argues this means they have nothing to do with antibiotic resistance in humans; Lawrence at Johns Hopkins says they may still contribute.) If you remove ionophores from the sales data comparison, the proportion of antibiotics that go to food-producing animals vs. humans drops to around 70 percent.
There are also also plenty of limits, as the FDA points out, on the usefulness of the publicly released sales data to inform public policy on antibiotics on farms. They don’t illuminate the reasons animals get the drugs (to promote growth? to treat infection? both?). They don’t specify how the antibiotics are administered (injection? food?).
The FDA’s asking for comments on how it might release more of the information it collects from animal drug companies, and says it will update reports from previous years with that new data.
That might include, for example, a detail it confirmed to Slaughter’s office in a 2011 letter — that nearly all antibiotics reported for animal use to the FDA were delivered in food and water, as opposed to by injection.
Meanwhile, the industry uses the current lack of detail to downplay the usefulness of the statistic, even as it fights efforts to gather and release more information.
Sales data is "not at all useful for understanding the benefits or the risks of using antibiotics to keep animals healthy," Ron Phillips of the Animal Health Institute told PolitiFact.
Others disagree and argue that the data is actually quite revealing.
"There is some uncertainty in these data, but not enough to escape the fact that the vast majority of antibiotics in this country are used in food animals, not to treat sick people," wrote Robert Lawrence, a doctor who directs the Center for a Livable Future at Johns Hopkins.
Slaughter, meanwhile, is sponsoring two bills, the Delivering Antimicrobial Transparency in Animals Act and the Preservation of Antibiotics for Medical Treatment Act, to require more detailed monitoring and to limit the use of antibiotics to sick animals. Among those lobbying against both: the Animal Health Institute.
Slaughter said "80 percent of the antibiotics in this country are fed to livestock."
The statistic comes from a comparison of FDA sales data for food-producing animals and private sales data for humans since 2009 — not all antibiotics sold in the United States. A letter from the FDA to the congresswoman confirms that most of the drugs for livestock are consumed in food and water. That means the percentage "fed" to animals may not be quite as high as 80 percent, though it would be close.
Slaughter could have said more clearly that of all the antibiotics sold for use by people and livestock, 80 percent are for animals. But she was close. We rate her statement Mostly True.