Antibiotic Administration to Farm Animals

Yesterday's New York Times features a superb front-page story by Matt Richtel about antibiotic resistance that passes to humans after originating from large quantities of antibiotics administered to farm animals; when people get ill from the resistant salmonella (or E. coli), multiple types of standard antibiotics are rendered useless. Maryn McKenna's 2017 book Big Chicken (subtitled "The Incredible Story of How Antibiotics Created Modern Agriculture and Changed the Way the World Eats") gave prominence to the story, and much detail. I had thought that the routine use of antibiotics on industrial farms came from the need to control disease in the terrible conditions on those farms, together with the breeding of animals with traits (such as fast growth) that are economically valuable but bring a health cost. This does seem to be the case, but I learned from Big Chicken that widespread administration of antibiotics to farm animals originated after it was discovered that the antibiotics themselves served as growth promoters. The use of antibiotics for growth promotion in livestock is now (since 2006) banned in the EU, and contravenes FDA guidelines in the US. (The World Health Organization also has weighed in.) There is some evidence that farm use of antibiotics (or antimicrobials) has been declining in the US and in the EU in recent years, though in the US, purchases of antibiotics for farm animals far exceed quantities purchased for human use.

Richtel's article highlights the difficulties that researchers and public health workers have in accessing farms and farm-level data, even when evidence points to farms as the source of outbreaks of resistant diseases in humans. The lack of access to farms risks prolongation of such outbreaks -- a high price to pay to allay concerns that some farms might have their reputations unfairly besmirched.