Much of the beef, pork or chicken we eat contains small amounts of antibiotics. The drugs are fed to animals so they can thrive in the crowded, often-fetid factory farms that dominate U.S. meat and poultry production.

But giving animals a steady diet of these medicines has contributed to the increase of antibiotic-resistant bugs that can pose grave risks to humans.

This isn’t news to the Food and Drug Administration, which has known since the early 1970s about the misuse of antibiotics in agriculture and done little about it. The agency seemed to be headed in the right direction in 1977, when it proposed a ban on using penicillin and two forms of tetracycline for animal weight gain after finding that the drugs “had not been proven to be safe.” Under pressure from Congress and drugmakers, the agency was ordered to hold hearings. It never did.

This month the FDA finally said it would issue rules for drugmakers and farmers to voluntarily stop putting antibiotics in animal feed and water to help them grow.

The guidelines will ask farmers to phase out the practice over the next three years. Pharmaceutical makers are to change the labels on their products, listing the approved uses.

Unfortunately, the loopholes are gaping. Even if farmers comply, they can still feed animals antibiotics for disease prevention, provided they get a veterinarian’s approval.

Nor is there much in the way of enforcement envisioned to discourage farmers or vets from engaging in off-label usage ― giving antibiotics to animals to aid growth. (Animals that are free of disease tend to grow faster, the argument goes.)

There also is reason to suspect that drugmakers won’t voluntarily retreat from a profitable market. About 80 percent of the antibiotics sold in the U.S., or 29 million pounds a year, are fed to animals. Heavy farm usage, in part, explains the trace amounts of antibiotics in soil samples and in 48 percent of the streams tested nationwide.

Many of these drugs, such as fluoroquinolones and cephalosporins, are front-line treatments for human illnesses such as urinary-tract infections and pneumonia. More and more of the bacteria that cause such diseases have become resistant to the drugs. The Alliance for the Prudent Use of Antibiotics estimates that resistant diseases account for $16 billion to $26 billion a year in annual medical expenses and $35 billion in lost time from work.

The U.S. has lagged behind much of the industrialized world in weaning farmers from antibiotics. In Denmark, which has adopted one of the strictest regimens for controlling the drugs, farmers have improved sanitation and avoid mingling of animal stocks. Hog production there now surpasses levels achieved with antibiotics while farmers’ costs have increased by only about 1 percent. More important, certain bacteria have shown declining resistance to the drugs.

It’s true that overuse of antibiotics in human health has contributed to resistance. But the U.S. medical community has made a concerted effort to curb this problem. In any case, according to the National Academy of Sciences, cutting human consumption won’t make much difference without reductions on the farm.

Last month, after an environmental group sued the FDA, a federal judge in New York ordered the agency to follow through with its 1977 withdrawal plan for penicillin and tetracycline unless drugmakers and the farming industry could prove that usage for weight gain is safe. This time the FDA should do what it intended 35 years ago and begin to decrease the amount of these drugs in the nation’s food chain.

Rather than waiting three more years to see how the new voluntary system works, Congress should pass the Preservation of Antibiotics for Medical Treatment Act. This bill, sponsored by New York Representative Louise Slaughter, a microbiologist by training, would phase out use of antibiotics in animals where no disease is present. Farmers would still be allowed to give the drugs to sick animals, or to temporarily treat others to prevent a diagnosed disease from spreading throughout a herd or flock. This would bring farm antibiotic use more in line with human medical standards.

Cutting antibiotic use may never turn back the genetic clock for microbes that have developed tolerance. But neither the FDA nor Congress should delay action in light of so stark a threat to human health.

(Bloomberg)