'Big Chicken' Connects Poultry Farming To Antibiotic-Resistant Bacteria

Enlarge this image toggle caption Charlie Neibergall/AP Charlie Neibergall/AP

The chicken for sale at your local grocery store isn't like the chicken your grandparents used to eat. They're bigger and more "breasty," says public health journalist Maryn McKenna — and that's by design.

"In the United States, we much prefer to eat white meat, and so we have bred chickens and genetically redesigned chickens in order for them to have a lot of breast meat," McKenna says. She attributes the change in poultry to factors like precision breeding, hormones and nutrition, but adds, "Antibiotics started this process."

Many large poultry farms feed antibiotics to their chickens in an effort to prevent disease. But McKenna says that humans who eat those chickens are at risk of developing not only antibiotic-resistant gastrointestinal infections, but also urinary tract infections as well. She chronicles the use of antibiotics in the poultry industry in her new book, Big Chicken.

McKenna's aim in writing the book is not to scare people away from eating poultry; rather, she hopes to improve the quality of the chicken we consume. "I think meat eating is going to remain with us as a culture," she says. "Therefore, I want to see meat producing get better, get better for the animals and also get safer for us. I do think it's possible to get there."

Interview Highlights

On how feeding antibiotics to chickens can lead to antibiotic-resistant foodborne infections in humans

When we give animals antibiotics, those antibiotics, for the most part, are given in their food and water. So they go into the animal's guts. They make some of those bacteria [in the gut] resistant. ... That bacteria contaminates [the animal's] meat. We eat the meat. And then we develop the foodborne illnesses that ... happen to be antibiotic-resistant. ...

Because of the consolidation of food production, in which now fewer very large firms are distributing their products over very large spaces, we get very large outbreaks of antibiotic-resistant foodborne illness that can be distributed hundreds and thousands of miles away from where the original farms are.

On how antibiotic-resistant bacteria in chickens can lead to urinary tract infections in women

Sometimes those [antibiotic-resistant] bacteria get out of our digestive systems and travel the short distance to our urinary systems, and then it feels just like a regular UTI. So a woman goes to her doctor and says, "I have a urinary tract infection." And the doctor will give her one of those standard set of antibiotics that are prescribed by medicine, and nothing happens. In other words, the antibiotic doesn't work because the infection is resistant.

Big Chicken The Incredible Story of How Antibiotics Created Modern Agriculture and Changed the Way the World Eats by Maryn McKenna Hardcover, 400 pages | purchase close overlay Buy Featured Book Your purchase helps support NPR programming. How?

But because so many people get UTIs so often — 6 to 8 million UTIs in women in the United States every year — that woman might go back to her doctor and the doctor will presume that she's been re-infected as opposed to the UTI never having been cured at all.

The reason why this is such a problem is that an untreated UTI gets worse and it can climb up the urinary system, into the kidneys, cause a kidney infection. The kidneys are a kind of back door to the circulatory system. So if the bacteria propagate through them, then you're looking at a bloodstream infection, infections in other organ systems, even septic shock, which can be deadly, all tracing back to antibiotic use on farms.

One pretty good estimate now is that of those 6 to 8 million UTIs that occur in women every year in the United States, possibly 10 percent could be foodborne UTIs, could be due to this antibiotic-resistant bacteria traveling from farms — which means 600,000 to 800,000 cases a year in this country.

On what to look for when reading labels on chicken meat

There definitely are things on labels on chicken that you should raise an eyebrow at, if you see them. Things like, for instance, "Raised without hormones," or "Raised cage-free." Well, hormones have never been legal for meat chicken in the United States, and similarly, meat chickens are never raised in cages. So those are both sort of claims that the companies can make that they don't really get any credit for.

A thing to look for is if it says, "No antibiotics ever," or sometimes, "Raised without antibiotics." And, to me, that is as significant a claim as "Organic." In some ways maybe more significant, because one of the weirdnesses of organic regulation in the United States is that the organic standard for meat chicken clicks in on day two of the chicken's life. So that chicken could've gotten antibiotics ... injected into it when it's still in the shell or in its first day of life. And that exposure might have been enough to generate resistant bacteria in that chicken's systems when it's a tiny, fluffy chick, even if it doesn't get antibiotics in the rest of its life.

To me, a label claim of, "Raised without antibiotics" is a thing that's really worth looking for.

On Perdue Farms moving away from antibiotic use

In 2014, Jim Perdue, who is the chairman of the very large chicken company Perdue Farms, the fourth-largest chicken company in the United States, called a press conference and announced that his family-owned company was turning away from routine antibiotic use. In fact, he said they had been doing this since 2007 and they were almost done with the process.

And now today, three years later, they are functionally 100 percent antibiotic-free — about 98 or 99 percent, depending on the year. That was such a shock to the industry that a number of other companies followed Perdue's lead, both in food production, so other chicken companies like Tyson, for instance, and also in food service, so companies like Chik-Fil-A and Subway and McDonald's and other fast-casual [restaurants] and larger companies.

Why did they do this? I have to say, not because they are explicitly concerned about antibiotic resistance. They did it because they're concerned about the reaction of their consumers. And Perdue themselves say they were getting about 3,000 comments a month from their customers questioning why routine antibiotics had to be used, in expressing discomfort with that process. And being intensely attuned to their customers, they decided to study, to figure out whether they could do away with routine antibiotics in their chickens, and it turns out that they could.

Heidi Saman and Thea Chaloner produced and edited the audio of this interview. Bridget Bentz, Molly Seavy-Nesper and Maria Godoy adapted it for the Web.