Resources: Antibiotic Use in Livestock and Resistance in Meat

I just posted on Agricultural Law on this topic and you may find the resources I relied on helpful. Much of the following is excerpted from my post:

 The FDA recently published its 2011 Summary Report on Antimicrobials Sold or Distributed for Use in Food-Producing Animals.  This report is required under the Animal Drug User Fee Amendments, codified in the Federal Food, Drug & Cosmetic Act at 21 U.S.C. § 360b. Sponsors of applications for new animal drugs that contain an active antimicrobial ingredient are required report to the FDA each year, providing data on the amount of sold or distributed for use in food-producing animals. The law also now requires that FDA make the information compiled public.

The National Antimicrobial Resistance Monitoring System (NARMS) also issued its 2011 report this month, reporting on the antimicrobial resistant bacteria it found on meat products. NARMS is a joint project of the FDA, the CDC and 11 state public health laboratories, and it tests retail meat products for the presence of antimicrobial resistant strains of bacteria.

Few major media outlets covered the release of these reports.  Fortunately, some food safety experts provided excellent commentary to explain the reports. Here are some important links.

• Dr. David Wallinga, Senior Advisor in Science, Food and Health at the Institute of Agriculture & Trade Policy wrote, Animal Antibiotic Use Continues Upwards, FDA Keeps Blinders On. 

• Bill Marler posted his thoughtful analysis on the Marler Blog, 2011 Retail Meat Report of the National Antimicrobial Monitoring System (NARMS) is Out.

• The Center for Infectious Disease Research & Policy at the University of Minnesota provided a very helpful summary, Bacteria in Meat Show Growing Drug Resistance, FDA Says, by Robert Roos.

• The Pew Campaign on Human Health and Industrial Farming published Record High Antibiotic Sales For Meat and Poultry Production, including its graphical representation of the use of antibiotics in the U.S.

• Helena Bottemiller at Food Safety News dug into the data and provided a helpful interpretation.  FDA Data: Slight Uptick in Animal Antibiotic Use, Resistance Remains Issue in Meat.

Some summary information:

Overall antimicrobial drug use in livestock production is up about 2.3%.  In 2011, 29.9 million pounds of antimicrobial drugs were used in livestock production. Contrast this with the 7.7 million pounds of antimicrobial drugs used for humans during the same time period.

Not all of the drugs used in livestock production are used for human treatment. The 2011 data shows a welcome decline in the use of Sulfa drugs, often used in humans. In contrast, Ionophores, which are not currently used to treat humans, showed an increase in animal use, largely in poultry production.

However, Dr. Wallinga noted that:

Penicillins and tetracyclines sold for animal use increased for the second year in a row. From 11.5 million pounds in 2009, sales rose to 14.4 million pounds in 2011. The two classes of antibiotics remain the most commonly used antibiotics in livestock and poultry, despite their obvious import for treating infections in people as well. In 2011, animal sales accounted for 38 percent of total penicillin sales and 98 percent of total tetracycline sales, including in humans.

One of the concerns about the overuse of antibiotics in livestock production is that we are encouraging the development of antibiotic resistant strains of dangerous bacteria. This is where the study of antimicrobial resistance in retail meat is important. Summarizing the NARMS report, Helena Bottemiller noted that:

Drug resistance among Salmonella isolates increased all around. In 2010, the percentage of isolates that showed drug resistance was about 50 percent, while in 2011 it had increased to nearly 55 percent. 

Resistance to cephalosporins, a class of drugs the FDA restricted in early 2012, increased between 2002 and 2011. Third generation cephalosporin resistance increased, in chicken from 10 to 33 percent and in ground turkey from 8 to 22 percent. . . .

The NARMS data also indicate that there was a significant increase in ampicillin resistance over the last decade among retail chicken, from nearly 17 percent to around 40 percent, and in ground turkey isolates from 16 percent to 58 percent. Ampicillin can be used in human medicine to treat infections, including Salmonella. 

More than 27 percent of all chicken isolates showed resistance to five or more classes of antibiotics and in ground turkey isolates researchers found 10 different serotypes with resistance to six or more classes of antibiotics.

The Animal Health Institute, the lobbying organization for the veterinary pharmaceutical companies has not commented on the recent reports, but has consistently maintained that "[a]nimal antibiotics make our food supply safer and people healthier. Antibiotics are a critical tool to prevent, control and treat disease in animals. In doing so, they also reduce the chance of bacterial transmission from animals to humans."  While antibiotics are clearly needed in animal production for the treatment of disease, the data indicates that their continual use in feed as a disease prevention method and to promote rapid growth is problematic.

Representative Louise Slaughter, a long time proponent of legislation to reduce antibiotic use in livestock production addressed the report through a press release titled, We Are Standing on the Brink of a Public Health Catastrophe.

Last October, IATP published a bibliography of studies, No Time to Lose: 147 Studies Supporting Public Health Action to Reduce Antibiotic Overuse in Food Animals.  

Susan Schneider