2015 in Review: Animal Antibiotics

By Lydia Zuraw on December 28, 2015

It’s difficult to summarize what happened on the animal antibiotics front this year. There were lots of pledges, lots of discussions and lots of reports, but not very many actions. Still, we still wanted to recap what happened in the 2015 regarding animal antibiotics. The Centers for Disease Control and Prevention (CDC) estimates that antibiotic-resistant infections sicken at least 2 million people every year and that more than 23,000 die as a result. Although the majority of these infections occur in healthcare settings, concern is growing over antibiotic-resistant infections from food and the contribution that subtherapeutic antibiotic use on farms (meaning below the dosage levels used to treat diseases) makes to resistance. Each year, antibiotic-resistant infections from foodborne germs cause an estimated 430,000 illnesses in the United States. Multi-drug-resistant Salmonella, from food and other sources, causes about 100,000 illnesses in the U.S. each year. Antibiotics are commonly used to promote the growth of food-producing animals and to prevent, control and treat disease. Overuse on farms can lead to resistant bacteria that cause infections in both animals and humans and could spread resistance genes from animal bacteria to human pathogens. By some estimates, about 80 percent of antibiotics sold in the U.S. are used in animals, though FDA cautions that it’s difficult to draw conclusions from direct comparisons between human and animal data because of differences such as population size (number of people compared to the number of animals in each of the many veterinary populations). An international issue In November the World Health Organization hosted the first World Antibiotic Awareness Week to help people learn more about antibiotics on both the human and animal side and try to prompt governments to take action. An analysis published in the Proceedings of the National Academy of Sciences estimated that livestock across the globe consumed about 63,151 tons of antimicrobials in 2010. They expect the number to increase by 67 percent by 2030. “More than 110 of the countries evaluated — mainly developing and emerging countries — do not yet have relevant legislation concerning appropriate conditions for the importation, manufacture, distribution and use of veterinary products, including antimicrobials,” wrote World Organisation for Animal Health Director General Bernard Vallat. “In some cases, legislation is totally non-existent. Where it does exist, it is very often not properly applied because of lack of public funds for the implementation of controls.” A couple weeks after the World Antibiotic Awareness Week, U.K.’s Review of Antimicrobial Resistance released a comprehensive report on antibacterial use in agriculture that recommends setting a global target for reduction. Disconcerting research Some interesting antibiotics research that came to our attention this year found that: antibiotic-resistant bacteria may travel via feedlot dust, a greater proportion of Shigella infections are now resistant to a very important antibiotic, and antibiotic resistance in some types of Salmonella infections is increasing. Most notably, scientists in China discovered a gene in E. coli that makes it resistant to a class of “last-resort” antibiotics and transfer resistance to other epidemic pathogens. The federal National Antimicrobial Resistance Monitoring System (NARMS) 2012 Retail Meat Report and an interim report for 2013 solely focused on Salmonella did have some encouraging findings which included a decrease in cephalosporin resistance among poultry and a decline in resistant Salmonella in retail chicken and ground turkey. The struggle for on-farm data Each year, FDA publishes a summary of the information animal drug sponsors are required to report every year by the Animal Drug User Fee Act (ADUFA), but the data are only broken down by drug class. An ongoing issue for the public health community is that sales and distribution information is not directly correlated with how the drugs are actually used and such information is needed to inform antimicrobial stewardship. According the ADUFA sales data from 2013, sales of medically important antimicrobials used in food-producing animals in the U.S. increased by 3 percent in 2013 and by 20 percent between 2009 and 2013. FDA also released the data for 2014 which showed another 3-percent increase in 2014 and 23 percent increase between 2009 and 2014. In May, FDA issued a proposed rule to expand animal drug data to include information about species. In comments about the proposal, many groups supported its finalization while also noting the need for on-farm use – especially purpose for use – in addition to sales data. In September, FDA held a public meeting alongside USDA and CDC to discuss possible approaches for collecting additional on-farm antimicrobial drug use and resistance data. Consumer groups supported the idea of obtain this use information from feed mills. The Veterinary Feed Directive rule, which was finalized earlier in the year, brings the use of antimicrobials in food-producing animals under veterinary supervision so that they are used only when necessary for assuring animal health. It also will require feed mills to keep records of use, so it’s already an aggregation of data and close enough to the farm to allow for species distinction. Attempts to reduce subtheraputic use The concerns surrounding FDA Guidance #213, which asks animal pharmaceutical companies to remove growth-promotion claims from medically important antimicrobial drugs in food-producing animals, were quieter in 2015 than in 2014. But the debate surrounding the guidance’s effectiveness is sure to rear its head at the end of 2016 as the voluntary policy goes into effect. In the meantime, California Gov. Jerry Brown has signed a bill which will enact requirements that go beyond what FDA has proposed thus far. The new law, which takes effect on Jan. 1, 2018, will ban subtherapeutic uses on farms and require that data be collected on antibiotic use. Antibiotic advocates in Congress also reintroduced their bills for banning non-therapeutic uses of medically important antibiotics in food animal production at the federal level. This included Rep. Louise Slaughter’s (D-NY) Preservation of Antibiotics for Medical Treatment Act (PAMTA) and Senators Dianne Feinstein (D-CA) and Susan Collins’ (R-ME) Prevention of Antibiotic Resistance Act (PARA). One of the bigger antibiotics stories of the year was President Obama’s declaration that it is now the policy of the federal government to encourage responsible use of antibiotics in the production of meat and poultry. This means supporting the supply chain for those products by directing federal departments and agencies to create a preference for acquiring them. And schools were given a new option for the type of chicken they purchase for school lunches – a USDA-verified standard that allows producers to use antibiotics only under the supervision of a veterinarian and only to appropriately control and treat disease, not to promote growth. More companies make judicious use pledges It became clear this year that chicken really is at the forefront of the shift to antibiotic-free sourcing. We learned that this is mostly likely chickens produced for food have short life spans — typically 42-45 days – so it’s easier to raise the birds with fewer or no antibiotics because there’s a lot less opportunity for any microorganisms. And making a swath of changes in order to reduce antibiotic use is easier to do in the vertically integrated production systems of companies like Tyson or Perdue because one company owns and controls multiple stages of production from the breeder flocks to the feed mill, the processing plant, etc. In April, Tyson Foods, the largest poultry producer in the U.S., announced it would strive to quit using human antibiotics in its chicken flocks by the end of September 2017. A few months later, Foster Farms, the California-based company linked to an outbreak of multi-drug resistant Salmonella Heidelberg that sickened 634 people in 2013 and 2014, introduced two new lines of antibiotic-free chicken. McDonald’s made lots of headlines in March when it announced that within two years, all of the chicken served at its 14,000 U.S. restaurants will come from farms which raised the birds without medically important antibiotics. Walmart began urging U.S. suppliers to its stores to adopt and implement judicious use principles for antibiotic use this year. And just this month, Papa John’s pledged to cut antibiotics from its chicken by summer 2016. Subway also said they plan to switch to chicken raised without antibiotics, but antibiotic preservationists were frustrated by the lack of details from the company. The sandwich chain was one of 20 chains that failed in a ranking of antibiotics policies and sourcing practices which was produced by several organizations including the Natural Resources Defense Council and the Center for Food Safety. A similar ranking of top turkey producers found that most allow routine antibiotic use. And on the pharmaceutical side of things, Elanco Animal Health announced a new antibiotic stewardship plan and pledged to host an animal health accountability summit in 2016 to provide a progress report on its efforts. Other stories of interest:

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