FDA and USDA officials sketched a multi-pronged approach to track antibiotic use on cattle, hog, chicken and turkey farms but acknowledged during a public meeting that they don’t have the funding to pay for what could be a labor- and time-intensive undertaking. If it is initiated, the on-farm data derived from the tracking could become part of a new inter-agency report to summarize antibiotic sales, use, livestock inventories, animal health and occurrence of bacteria resistant to the drugs.
It all would be part of the government-wide drive to preserve the effectiveness of antibiotics for treating human illness.
“We don’t have decades to extricate ourselves,” said acting FDA commissioner Stephen Ostroff, referring to the health threat posed by bacterial resistance. Judicious use of antibiotics is vital, he said.
USDA chief veterinarian John Clifford said efficacious medicines were needed for people and livestock. “We need to protect human health. We also have to protect animal health.”
The administration’s National Action Plan calls for enhanced monitoring of antibiotic-resistance patterns as well as sales, usage and management practices during production of food animals and meat sold at grocery stores. The FDA monitors antibiotic sales and the CDC compiles data on bacterial resistance. The USDA conducts periodic surveys and studies of antibiotic use on livestock farms. The USDA’s data-gathering would become more extensive and routine under the proposals outlined at the public hearing.
Meanwhile, the FDA is phasing out the use of medically important antibiotics as livestock growth promotants. After December 2016, the drugs would be available only for treatment and prevention of disease under veterinary supervision. Ostroff said 30 products already were withdrawn from sub-therapeutic use.
“USDA data collection programs will play a key role” in assessing the effect of the change in rules on antibiotic use, said Ostroff. Officials would like to begin on-farm data collection in 2016. The first round of material would form a baseline of antibiotic use and could cover points such as when, why, how long, and in what doses antimicrobials are used. The material could be compared to tests for pathogens in livestock, in packing plants and in food, as well as the regions and times when resistant bacteria are found. “The clock is ticking,” said the acting commissioner. “December 2016 is not that far away.”
So far, Clifford said, Congress has declined to earmark money for expanded monitoring of antibiotics in agriculture.
In order to gather on-farm data in 2016, the government would have to finalize its collection plan early next year. The FDA will accept comments on the question until Nov. 30. “This is definitely a work in progress,” said Bill Flynn of FDA. The first inter-agency summary of antibiotic use and management could appear in 2018.
Animal agriculture is the major consumer of antibiotics. Drug makers reported sales of 14.6 million kg of antimicrobials approved for use in food animals in 2012, up 16 percent from 2009. Some 61 percent of the sales were medically important antibiotics. A report on sales in 2013 is in the pipeline, said an FDA press aide.
In May, the FDA proposed that drug companies estimate the amount of their antibiotics that are consumed each year by cattle, hogs, chickens and turkeys. “We want something that measures use,” said Flynn. In response to a question from the audience about using veterinarians as a source of information about antibiotic use, he said, “There’s good reason to think about if that would be a good way.”
USDA officials listed four possible routes for gathering data on livestock use of antibiotics. They ranged from studies that could last two years and involve repeated visits to farms to gather samples from animals and information from producers to putting more questions about antibiotics into surveys of producers, data-mining of past surveys, tapping the databases of USDA disease laboratories or seeking information from livestock organizations. “We would be looking at both use and resistance patterns,” said USDA biostatistician Kathe Bjork.
Key to data collection, said USDA officials, is voluntary cooperation by producers, which would require assurance that their information remains confidential. Farmers are notoriously prickly about outsiders nosing into their business.
James MacDonald, of the USDA’s Economic Research Service, said smaller producers are more likely to participate in surveys than larger producers, who account for the bulk of livestock output, so there are challenges in assuring on-farm data would be representative of the industry. Funding must be assured to protect the integrity of multi-year surveys. One USDA official said the 2013 government shutdown ruined a study of antibiotics in cattle and pathogens in meat; the animals were shipped to slaughter while the scientists were idled.