“We’re trying to be stewards and leaders at the same time,” said Mr. Simmons, adding that the brochure “wasn’t misrepresentation, necessarily, relative to the label or the science, or how a farmer would look at it.”
Dr. Shabbir Simjee, Elanco’s chief medical officer, said drugs like those in the campaign “would never be administered” in a herd “without some animals being physically sick,” adding that “there would need to be some animals showing clinical signs.”
He likened treating a herd to caring for children in a nursery: “If one child gets sniffles, you usually find that the whole class ends up with a cold, and this is exactly the same principle.”
But children almost certainly would not all be treated with preventive antibiotics in such a situation, and many scientists believe animals often should not be treated that way, either.
The connection of overuse of antibiotics in livestock to human health takes two paths: As bacteria develop defenses against drugs widely used in animals, those defense mechanisms can spread to other bacteria that infect humans; and, resistant germs are transmitted from livestock to humans — through undercooked meat, farm-animal feces seeping into waterways, waste lagoons that overflow after natural disasters like Hurricane Florence, or when farm workers and others come into contact with animals.
[Read other articles in our series Deadly Germs, Lost Cures.]
New F.D.A. regulations put in effect in the waning days of the Obama administration prohibited farms from fattening livestock by lacing their feed with medically important antibiotics. The new rules, along with rising consumer demand for antibiotic-free meat, cut antibiotic use significantly in 2017. But such drugs are still routinely given to pigs and cattle, accounting for almost 80 percent of medically important livestock antibiotics in the United States and nearly 5,000 tons of active ingredient. Worldwide use is projected to keep rising sharply as growing middle classes in places like China and Brazil demand more meat.
Ellen Silbergeld, a professor at Johns Hopkins University, who has worked with the W.H.O. on drug resistance, called the continuing promotion of the drugs by pharmaceutical companies “very dangerous.”