ARUN RATH, HOST:
This week, McDonald's announced that in two years, their 14,000 restaurants in America will serve chicken raised without most antibiotics. That's not just big news for chickens - as the use of these antibiotics in animals raised for meat has increased, so has the incidence of drug-resistant, sometimes life-threatening bacteria afflicting humans. Maryn McKenna writes for WIRED magazine and is the author of "Superbug."
MARYN MCKENNA: This is really a big deal. And anytime you talk about something that McDonald's does, it means that it's a buyer really at the top of the market. And it's therefore very likely that whatever they do is going to set a model. And that is something that people have been wanting the meat industry to move toward for decades now.
RATH: Now, you mention there's an exception to this ban on antibiotics. They can still use some drugs - some antibiotics on chickens. How big a deal is that?
MCKENNA: You can construe it as a kind of spectrum. And at one end of the spectrum, there's giving antibiotics for diseases for when animals are sick - and no one disagrees with that. And on the other end, there's this practice that's been under scrutiny since the 1970s called growth promotion in which you give tiny doses of antibiotics - doses that would never cure anything - to animals routinely in their food or water so that they put on muscle meat faster and they can be sold faster. In between those two, there's a kind of mushy middle in which drugs are given to prevent disease - it's called prophylaxis or metaphylaxis - to protect animals against the conditions that they're held in. And what McDonald's has said is that they will continue some of that mushy middle practice by using a particular class of antibiotics called ionophores. And a lot of public health people are actually okay with this. The reason is because ionophores aren't used in human medicine. So if using them on the farm creates antibiotic-resistant bacteria, then this is not going to be so much of a problem because ionophore-resistant bacteria wouldn't be significant for humans.
RATH: So do we expect this decision by McDonald's to make a dent in the problem of antibiotic-resistant bacteria?
MCKENNA: Well, I certainly hope so. The science is really good at this point and has been for decades that in countries where they've been restricting antibiotic use for a while - that's most of Scandinavia, parts of Western Europe, the Netherlands is a particularly good example - it does look like resistant bacteria affecting humans trend down once you start to take antibiotics out of the agricultural system. It takes a while and there's a lot of other input so sometimes it's hard to tease out the effect but it has to have a good result.
RATH: You think McDonald's, you think hamburgers - so what about antibiotics being given to cows or pigs for that matter?
MCKENNA: Right, so McDonald's has not said anything about that yet. However, that they did it in chicken is still really significant because in the United States, chicken is the meat that we eat the most of - we eat much more chicken. So that they are moving to take antibiotics out of the meat that Americans eat the most of is a real market leader and one can only hope that that's going to move on to other meat sectors too.
RATH: Maryn McKenna writes for WIRED and is the author of the book "Superbug." Maryn, thank you.
MCKENNA: Thank you for having me. Transcript provided by NPR, Copyright NPR.