New data released yesterday by the US Food and Drug Administration (FDA) shows that the amount of medically important antibiotics sold and distributed for use in food-producing animals rose by 9% between 2017 and 2018, after a 3-year decline.

Overall, the FDA says, 2018 is the still the second-lowest sales year on record, and sales of medically important antibiotics for use in livestock are down 21% from 2009, the first year of sales data reporting, and 38% from the peak sales year of 2015.

The agency also notes that a rebound in sales is not a surprise after the 2017 implementation of new rules that banned the use of medically important antibiotics for growth promotion and required veterinary oversight for use of antibiotics in water and feed.

Although sales and distribution figures do not reflect how the antibiotics are actually being used on farms, they are the best indicator currently available, and experts say the increase is still worrisome, because widespread use of these drugs—which are also used to treat human infections—in meat production is contributing to rising antibiotic resistance.

"I'm disheartened by the fact that we have an increase in antibiotic sales," said veterinary and public health consultant Gail Hansen, DVM. "I'm concerned that we're going in the wrong direction."

Increases seen in pigs, cattle

Of the more than 6 million kilograms of medically important antibiotics sold to farmers, 42% were used in cattle, 39% in swine, 11% in turkeys, and 4% in chickens. While the amount sold for use in chickens declined 17% from 2017, sales of antibiotics for swine and cattle rose by 17% and 8%, respectively, and increased for turkeys by less than 1%.

The most frequently sold class of medically important antibiotics in 2018 for use in livestock were tetracyclines, which accounted for 66% of all medically important antibiotic sales. Penicillins accounted for 12% of sales, and macrolides for 8%. Sales of those three classes rose in 2018, by 12%, 6%, and 1%, respectively.

The decline in chicken antibiotic sales follows a 47% drop from 2016 to 2017 and likely reflects the poultry industry's ongoing consumer-driven shift to raising chickens without the routine use of medically important antibiotics. Over the past few years, several major fast-food chains and large poultry producers have committed to phasing out medically important antibiotics in poultry production in reaction to consumer demand. But that movement has been slower to take hold in the beef and pork industries.

"We've seen over the past several years, chicken producers have made significant progress in reducing antibiotic use, whereas the beef and pork industries have continued to lag behind," said Matt Wellington, antibiotics campaign director for US PIRG (Public Interest Research Groups). "We know that the chicken industry is doing the right thing on antibiotics, and the beef and pork industries need to follow suit, because there's no good reason to delay preserving life-saving medicines for the future."

Hansen agrees. While reducing antibiotic use in the beef and pork industries presents different challenges than it does in chicken because cattle and swine live longer and have more exposure to stress and infection risks, Hansen notes that other countries—particularly Denmark and the Netherlands, which have seen significant declines in antibiotic use in pigs—have found ways to use fewer antibiotics in these animals.

"We don't have any more disease than they do in other parts of the world," she said. "It comes down to market forces and political will."

Wellington said the increase is further evidence that the FDA needs to move faster to set limits on how long medically important antibiotics can be used to prevent or treat disease in food-producing animals. Currently, according to the group Keep Antibiotics Working, almost 40% of medically important antibiotics approved for use in food animals have no duration limit. US PIRG is recommending that the limit be set at 21 days.

"That is a reasonable benchmark to ensure that we are giving as little opportunity to bacteria that are resistant to the drugs to flourish in those conditions," he said.

The FDA has said that it's currently gathering information on duration limits and that it intends to develop and implement a strategy to ensure that all medically important antibiotics are labeled with "an appropriately targeted duration of use."

Preventive use remains an issue

Wellington also argues that the FDA needs to go a step further and restrict the use of medically important antibiotics on US farms to treating sick animals or controlling a verified disease outbreak. The agency currently allows farmers to use medically important antibiotics in feed and water to prevent disease in healthy animals, a common practice that Wellington says is used to protect against diseases that are brought on by "unsanitary, overcrowded, and stressful living conditions."

The World Health Organization (WHO), along with many infectious disease and antibiotic-resistance experts, has said that the practice of using medically important antibiotics for disease prevention contributes to the emergence of antibiotic resistant pathogens and should end.

But the FDA considers using antibiotics for disease prevention to be "necessary and judicious," and so far has not indicated that it has any plans to restrict antibiotic use to treatment. And the US Department of Agriculture openly disputed the WHO recommendation when it was issued in 2017, arguing that it wasn't supported by sound science.

Hansen says that if the FDA did put restrictions on preventive use of medically important antibiotics, other countries would likely follow.

"If we're really serious about trying to decrease antibiotic resistance…the US has to be one of the leaders, and not one of the laggers, in that fight" Hansen said. "So far, we have not been a leader."

The report comes less than a month after the Centers for Disease Control and Prevention (CDC) issued a report estimating that antibiotic-resistant bacteria cause more than 2.8 million infections and 35,000 deaths a year.

"At a time when the CDC is now estimating 1 person dies every 15 minutes from drug-resistant infections, we need to do everything we can to reduce antibiotic use, and a lot of that is going to have come down to how we raise meat in this country," Wellington said.

See also:

Dec 10 FDA 2018 summary report