In the United States, the consumption of antibiotics in farm animals is increasing, while medical use is decreasing


Sales of medically important drugs for farm animals are almost twice as high as those for human medicine

By David Wallinga NRDC and Eili Klein and Alisa Hamilton, Center for Disease Dynamics, Economics & Policy

Experts estimate that there will be up to 10 million deaths from drug-resistant infections worldwide by 2050 unless policymakers take more effective measures to keep us safe. Antibiotic-resistant bacteria, sometimes called superbugs, cause more than 2.8 million infections and contribute to 35,000 to 162,000 deaths in the United States each year.

Using any antibiotic in any location can increase resistance to any other antibiotic in another location. Therefore, it is especially important to avoid inappropriate or unnecessary use. Containing resistance requires much smarter use of these valuable drugs. This applies in particular to agricultural operations and in human medicine – the two largest application categories by far.

The intensive use of antibiotics in livestock farming has long been a public health problem. The US Food and Drug Administration (FDA) has spent the past decade encouraging the US animal industry to use antibiotics more prudently, mostly on a voluntary basis. However, the latest FDA data seems to confirm that antibiotic overuse continues. Livestock sales have increased for two years in a row, after a brief decline from 2015 to 2017.

FDA sales data alone are not a sufficient guide to a clear understanding of antibiotic use on U.S. farms and ranches. Unfortunately, there is no system in the USA to fully track the actual use of medically important antibiotics. Such a system could produce parallel reports comparing how these precious drugs are being used in different settings. Collecting antibiotic use data at the farm level would provide the granularity necessary to understand how often and how many antibiotics US farms are using and why they are being used.

According to the Centers for Disease Control and Prevention (CDC), the “slow” pandemic of antibiotic resistance can best be tackled with a “one health” approach. Such an approach would be, for example, one that takes a holistic approach to antibiotic consumption and levels of resistance in the human population, in animals and in the environment. Since 2009, the FDA has reported annual sales of antibiotics for farm animals, but has not reported any veterinary prescriptions or orders; Human sales data is also not reported. The CDC now publishes annual reports on the prescribing of antibiotics in human medicine, but these publications do not include national data on medical antibiotics sales.

Our new analysis. For the third time since 2017, NRDC and the Center for Disease Dynamics, Economics & Policy (CDDEP) have teamed up to close critical data gaps on antibiotic use in the United States. Table 1 and the accompanying figure provide both the FDA’s annual data on animal sales of medically important antibiotics for the years 2009 to 2019 as well as the estimated uses of the same drugs in human medicine. To estimate human usage, CDDEP used data from IQVIA, a private company that directly About US Ambulatory Antibiotic Prescribing Total medical antibiotic consumption was estimated by combining ambulatory data with estimates of hospital prescriptions.

A head-to-head comparison of the same medically important antibiotics sold for livestock and used in human medicine allows a better assessment of key differences and patterns. The use of antibiotics in human medicine has remained constant since 2009. It has actually decreased slightly since 2017, despite the increase in the US population compared to the previous year. In contrast, sales of these medicinal products for livestock farming rose by 11.3% from 2017 to 2019, from 5.6 million kg to 6.2 million kg. The sale of farm animals is now almost twice as high as that of human medicine (6.19 million kg vs. 3.30 million kg).

From 2009, farm animal antibiotic sales peaked through 2015 before declining in 2016 and 2017. This was the period when the FDA first asked the livestock sector to stop marketing and selling medically important antibiotics in animal feed for the purpose of promoting growth. The growth-promoting use of feed antibiotics was banned in January 2017. All remaining feed uses have also been placed under veterinary supervision, which means that a veterinarian must issue a prescription or a veterinary “feed policy” before a feed mill mixes medically important antibiotics in animal feed and distributes them to producers. In the context of these feed guidelines, however, many livestock antibiotics are routinely fed to animal herds for so-called disease prevention, even if there are no sick or sick animals.

The net increase in livestock sales since 2017 is solely due to the fact that more antibiotics are sold for use in pig and cattle production. During those two years, sales of pigs increased by around 560,000 kg, or nearly 28%, as shown in Table 2. Cattle sales also rose by a more modest 8%. Sales of medically important antibiotics for pigs and cattle combined are 55% higher than sales of these pharmaceuticals for human patients.

As mentioned earlier, the FDA’s current coverage of antibiotic sales is inadequate. Ideally, the FDA would provide more context to the sales figures by also reporting the relative size of the animal population in production. The FDA proposed this in 2017, but did not implement it.

We used the U.S. Department of Agriculture’s Quickstat tool to determine the number of adult pigs slaughtered annually in the U.S. from 2017 to 2019. The total number of pigs slaughtered is a reasonable guide to the size of the pig population most likely to receive all pig antibiotics sold that year. We found data suggesting that the size of this pig population increased by about 7% from 2017 to 2019. Therefore, higher production levels alone cannot explain the 28% increase in sales of pig antibiotics.

FDA has to do better. The FDA should immediately follow up and start reporting antibiotic sales, based on the size of the animal population most likely to receive these drugs, as suggested in 2017. This data should also be integrated into a federal system that will be comprehensively tracked and then fully provided -integrated reports on antibiotic use and resistance in humans, the environment and animals – especially farm animals.

The CDC states that 75% of new dangerous infections, including pandemics, spread from animals to the human population. These animal-borne threats include viruses, as well as new forms of antibiotic resistance genes and the multi-resistant super bacteria that carry them. Preparing for a pandemic and protecting public health should be our nation’s number one priority. We must therefore invest heavily in tracking antibiotic resistance and antibiotic use wherever it occurs.


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