The American Meat Institute (AMI) reported today that new federal data show that E. coli O157:H7 is found in less than one quarter of one percent of ground beef samples, a 72 percent decline since 2000 in ground beef samples testing positive for the pathogen.

The data are from Food Safety and Inspection Service (FSIS) 2010-year end results of microbiological samples for raw ground beef products analyzed for E. coli O157:H7.  In 2010, there were 29 positive samples out of 11,616 taken in federal plants, no positives of 905 samples taken in retail stores and one positive out of 29 imported samples.  The overall prevalence rate was 0.24 percent.  The year-end data is available here.

According to the FSIS, criteria for sampling and analytical methodology for E. coli O157:H7 testing can be drawn from Agency guidance published in August 2008 Draft Compliance Guideline for Sampling Beef Trimmings for E. coli O157:H7 and Draft Guidance for Small and Very Small Establishments on Sampling Beef Products for E. coli O157:H7, and the Federal Register Notice on FSIS testing methodology [Docket No. FSIS-2008-0007] Revised FSIS Testing Methodology for Escherichia coli (E. coli) O157:H7 The sampling and testing comparison standards for ground beef product and beef manufacturing trimmings are N60 sampling for trim, testing most of the sample (or at least 325 grams) in the lab, and applying a screening or culture method designed and validated for detecting the lowest possible levels of sub-lethally injured E. coli O157:H7 cells.

The real question is if greater sampling amounts (greater than N60) and testing more often would continue to show this positive trend?