Redesign of FSIS Sampling Methodologies
 

To Improve Detection of E. coli O157:H7
 

United States Department of Agriculture 

Food Safety and Inspection Service 

Office of Data Integration and Food Protection 

Data Analysis and Integration Group 

Sarah Berg-Devney 

Lead Government Analyst 

March 2012 

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Table of Contents
 SUMMARY................................................................................................................................................ 6
 

1.0 INTRODUCTION ........................................................................................................................... 8
 

2.0 OPTIONS FOR REDESIGN OF FSIS E. COLI O157:H7 SAMPLING PROGRAMS ............... 10
 

3.0 AVERAGE E. coli O157:H7 POSITIVE RATES......................................................................... 11
 

3.1 Ground Beef Sampling ................................................................................................................... 11
 

3.2 Beef Trim........................................................................................................................................ 11
 

3.3 Bench Trim ..................................................................................................................................... 12
 

3.4 Raw Ground Beef Components Other Then Trim.......................................................................... 12
 

4.0 TARGET ESTABLISHMENTS WITH E. COLI O157:H7 POSITIVES..................................... 14
 

4.1 E. coli Positive in Routine Testing of Beef Trim (MT50).............................................................. 14
 

4.2 E. coli O157:H7 Positive Follow-Up Sampling ............................................................................. 14
 

5.0 TARGET VOLUME CLASSES WITH LARGER VOLUMES........................................................ 16
 

5.1 E. coli O157:H7 Percent Positive for Different Volume Classes .............................................. 16
 

6.0 TARGET VOLUME CLASSES WITH LARGER E. coli PERCENT POSITIVE ...................... 18
 

7.0 TARGET VOLUME CLASSES WITH LARGER VOLUME-WEIGHTED PERCENT 

POSITIVE................................................................................................................................................. 20
 

8.0 TARGET ESTABLISHMENTS ASSOCIATED WITH E. COLI POSITIVES IN RAW 

GROUND BEEF....................................................................................................................................... 23
 

9.0 TARGET ESTABLISHMENTS WITH HIGHER HACCP NON-COMPLIANCES .................. 26
 

9.1 Beef Trim Establishments............................................................................................................... 26
 

9.2 Beef Trim Suppliers........................................................................................................................ 27
 

10.0 TARGET ESTABLISHMENTS WITH SANITARY DRESSING NON-COMPLIANCES ....... 30
 

11.0 INCREASE SAMPLING DURING THE SUMMER MONTHS................................................. 31
 

11.1 Seasonality of E. coli O157:H7 Positives..................................................................................... 31
 

11.2 Seasonality of 03J01 and 03J02 Health-Related Noncompliances............................................... 32
 

12.0 INCREASE THE COLLECTION RESPONSE RATE................................................................. 33
 

13.0 MISCELLANEOUS ...................................................................................................................... 35
 

13.1 Geographical Distribution of Beef Trim E. coli O157:H7 Positives............................................ 35
 

13.2 Beef Trim Versus Veal ................................................................................................................. 35
 

14.0 DISCUSSION AND RECOMMENDATIONS............................................................................. 37
 

15.0 STATISTICAL SAMPLING DESIGN ......................................................................................... 40
 

15.1 Sampling Frame...................................................................................................................... 40
 

15.2 Sample Size ............................................................................................................................ 40
 

15.3 Annual Sampling Floor .......................................................................................................... 40
 

15.4 Monthly Sampling Ceiling ..................................................................................................... 40
 

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15.5 Sampling Weights................................................................................................................... 41
 

15.5.1 Scaling Factors on Volume Scores ..................................................................................... 42
 

15.5.2 Calculating Probability of Selection ................................................................................... 42
 

15.6 Historical Collection Rates..................................................................................................... 42
 

15.7 Theoretical Sampling Distribution ......................................................................................... 43
 

15.8 Increased ability to detect E. coli O157:H7............................................................................ 43
 

15.9 Prevalence estimation............................................................................................................. 44
 

16.0 REFERENCES .............................................................................................................................. 45
 

17.0	 APPENDECIES............................................................................................................................. 46
 

Appendix A - N60 Sample Collection Method..................................................................................... 46
 

Appendix B - Volume-Weighted E. coli Percent Positive in Beef Trim.............................................. 47
 

Appendix C - Probability of Detection of Beef Trim E. coli O157:H7 Positives ................................ 50
 

Appendix D - Procedures Codes........................................................................................................... 56
 

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List of Tables
 Table 3- 1 E. coli O157:H7 Test Results for Raw Ground Beef .............................................................. 11
 

Table 3- 2 MT50 E. coli O157:H7 Test Results for Beef Trim................................................................ 12
 

Table 3- 3 MT55 E. coli O157:H7 Test Results for Bench Trim ............................................................. 12
 

Table 3- 4 MT54 E. coli O157:H7 Test Results for Ground Beef Components ...................................... 13
 

Table 4- 1 Probability of MT50 E. coli Positive in 120 days following an MT50 E. coli Positive.......... 14
 

Table 4- 2 MT53 Follow-Up Test Results for Beef Trim......................................................................... 15
 

Table 4- 3 MT53 Follow-Up Test Results for Bench Trim...................................................................... 15
 

Table 4- 4 MT53 Follow-Up Test Results for Other Components........................................................... 15
 

Table 5- 1 Volume Classes for Beef Trim MT50 E. coli O157:H7 Sampling for 2007-June 2011........ 16
 

Table 5- 2 Volume Classes for Bench Trim MT55 E. coli O157:H7 Sampling for 2009- June 2011 .... 17
 

Table 5- 3 Volume Classes for Other Ground Beef Components MT54 E. coli O157:H7 Sampling for 

2008-June 2011......................................................................................................................................... 17
 

Table 6- 1 Distribution of Samples per Beef Trim Plant if Sampling Proportional to Percent Positive .. 18
 

Table 6- 2 Distribution of Samples per Bench Trim Plant if Sampling Proportional to Percent Positive 19
 

Table 6- 3 Distribution of Samples per Other Ground Beef Component Plant if Sampling Proportional
 

to Percent Positive..................................................................................................................................... 19
 

Table 7- 1 E. coli O157:H7 Beef Trim Volume-Weighted Percent Positive............................................ 20
 

Table 7- 2 Distribution of Samples per Beef Trim Plant if Sampling Proportional to Volume Weighted 

Percent Positive......................................................................................................................................... 21
 

Table 7- 3 E. coli O157:H7 Bench Trim Volume-Weighted Percent Positive........................................ 21
 

Table 7- 4 E. coli O157:H7 Other Component Volume-Weighted Percent Positive .............................. 22
 

Table 8- 1 MT52 E. coli O157:H7 Test Results for Suppliers ................................................................ 23
 

Table 8- 2 MT52 E. coli O157:H7 Test Results for Beef Trim and Other Suppliers.............................. 24
 

Table 8- 3 MT52 E. coli O157:H7 Test Results for Sole Suppliers ........................................................ 24
 

Table 8- 4 MT52 E. coli O157:H7 Test Results for Sole Beef Trim and Other Sole Suppliers.............. 24
 

Table 9- 1 Health-Related Noncompliance Rates for Beef Trim Establishments With and Without E. coli
 

O157:H7 Positives during MT50 Sampling ............................................................................................. 26
 

Table 9- 2 Beef Trim Establishment 03J01 and 03J02 Health-Related Non-compliances in the Months 

Table 9- 3 Probability Beef Trim Establishment Has an E. coli Positive in 3 Months Following an 03J02 

Table 9- 5 Probability Beef Trim Supplier Has an E. coli Positive in 3 Months Following an 03J01 

Preceding an E. coli Positive in Beef Trim............................................................................................... 27
 

Inspection.................................................................................................................................................. 27
 

Table 9- 4 03J01 and 03J02 Health-Related Noncompliance Rates for Beef Trim Suppliers ................. 28
 

Inspection.................................................................................................................................................. 28
 

Table 11- 1 E. coli O157:H7 Positives by Month 2007-June 2011......................................................... 31
 

Table 11- 2 E. coli O157:H7 Percent Positive Seasonality May-Oct 2007-June 2011 ........................... 31
 

Table 11- 3 Beef Trim Establishment 03J01 and 03J02 Health-Related Noncompliance Rates............. 32
 

Table 11- 4 Supplier Establishment 03J01 and 03J02 Health-Related Noncompliance Rates................ 32
 

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Table 12- 1 Expected Number of E. coli Positives if Collection Response Rate Increased to 60 or 70 

Table 12- 2 Expected Number of Beef Trim E. coli Positives under Sampling Proportional to E. coli
 

Percent Positive with at Least One Sample per Establishment and Increased Collection Response Rates
 

Percent....................................................................................................................................................... 33
 

................................................................................................................................................................... 34
 

Table 13- 1 Geographical Distribution of Beef Trim E. coli O157:H7 Positives..................................... 35
 

Table 13- 2 E. coli O157:H7 Percent Positive in Ground Beef and Ground Veal ................................... 36
 

Table 13- 3 E. coli O157:H7 Percent Positive in Beef Trim and Veal Trim............................................ 36
 

Table 15- 1 Monthly Sampling Ceilings and Annual Sampling Floor by Production Volume Group .... 41
 

Table 15- 2 Calculation of Sampling Weights by Production Volume Group ......................................... 41
 

Table 15- 3 Historical Collection Rates by Production Volume Group ................................................... 43
 

................................................................................................................................................................... 43
 

Table 15- 4 Theoretical Monthly and Annual Sampling Distribution with Estimated Annual Collection
 

Table 15- 5 Computation of Increased Ability Compared to Previous Current Design........................... 44
 

Table B- 1 Volume Groups for Beef Trim Sampling ............................................................................... 47
 

Table B- 3 E. coli O157:H7 Percent Positive for Beef Trim as a Function of Beef Trim Volume 

Table B- 4 E. coli O157:H7 Beef Trim Volume Weighted Percent Positive for Years CY2007 - June 

Table B- 2 Beef Trim Volume of Establishments Tested for E. coli O157:H7........................................ 47
 

Produced for the Years CY2007 - June 2011 ........................................................................................... 48
 

2011........................................................................................................................................................... 48
 

Table B- 5 E. coli O157:H7 Volume Weighted Percent Positives for Beef Trim by Year ...................... 49
 

Table C- 1 Expected Number of Beef Trim E. coli Positives under Sampling Proportional to Volume . 50
 

Table C- 2 Expected Number of Beef Trim E. coli Positives under Percent Volume Sampling Program
 

Table C- 3 Expected Number of Beef Trim E. coli Positives under Sampling Proportional to E. coli
 

Table C- 4 Expected Number of Beef Trim E. coli Positives under Sampling Proportional to E. coli
 

Table C- 5 Expected Number of Beef Trim E. coli Positives under Sampling Proportional to Volume 

Table C- 6 Expected Number of Beef Trim E. coli Positives under Sampling Proportional to Volume 

Table C- 8 Expected Number of Beef Trim E. coli Positives under Sampling Proportional to E. coli
 

Percent Positive with at Least One Sample per Establishment and 60% of Total Samples are Taken
 

During May - Oct...................................................................................................................................... 55
 

with at Least One Sample per Establishment. .......................................................................................... 51
 

Percent Positive......................................................................................................................................... 52
 

Percent Positive with at Least One Sample per Establishment................................................................. 52
 

Weighted Percent Positive ........................................................................................................................ 53
 

Weighted Percent Positive with at Least One Sample per Establishment................................................ 54
 

Table C- 7 Seasonality of Beef Trim E. coli Percent Positive.................................................................. 54
 

Table D- 1 Procedure Code Description................................................................................................... 56
 

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SUMMARY
 

The objective of this report is to evaluate the Food Safety and Inspection Service’s (FSIS) E. coli 

O157:H7 sampling designs for testing beef trim, bench trim, and raw ground beef components other 

than trim to determine options for increasing the degree of confidence for detecting E. coli O157:H7 

positives during FSIS verification testing. Ten options for focusing E. coli testing primarily on 

establishments with the highest probability of producing beef trim or components contaminated with E. coli 

O157:H7 were evaluated. They are to increase E. coli O157:H7 sampling frequency in 

Establishments with E. coli O157:H7 positives 

Volume classes with higher production volumes 

Volume classes with higher E. coli O157:H7 percent positive 

Volume classes with higher volume-weighted E. coli O157:H7 percent positive 

Beef trim and other component supplier establishments associated with E. coli O157:H7 positives in 

raw ground beef 

Establishments with higher HACCP noncompliances 

Establishments with higher sanitary dressing noncompliances 

Seasons of the year with higher E. coli O157:H7 positives 

Geographic regions with higher E. coli O157:H7 percent positive 

Product categories with higher E. coli O157:H7 percent positive 

The impact of increasing the collection response rate is also evaluated. 

The major observations were: 

Over the period 2007-June 2011, beef trim sampling produced 31 E. coli O157:H7 positives (0.60% 

positive rate), bench trim sampling produced 2 positives (0.19% positive), and raw ground beef 

components other than trim sampling produced 2 positives (0.28% positive). Within each of these 

three sampling programs, there is no statistically significant difference in the E. coli O157:H7 

percent positives between years. 

The E. coli O157:H7 percent positive in beef trim (0.60%), bench trim (0.19%) and raw ground 

beef components other than trim (0.28%) are not statistically significantly different. 

The E. coli O157:H7 percent positive in beef trim (0.60%) is statistically significantly higher 

than that found in raw ground beef (0.27%). The probability of detecting an E. coli O157:H7 

positive in beef trim is 2.2 times higher than in raw ground beef (two sided Exact Fisher, p < 

0.0002). The E. coli percent positives in bench trim (0.19%) and raw ground beef components 

other than trim (0.28%) are not statistically significantly different than that found in raw ground 

beef (0.27%). 

The probability of detecting an E. coli O157:H7 positive during follow-up sampling after an E. 

coli O157:H7 positive in a beef trim establishment is 6.6 times higher than under routine beef 

trim E. coli sampling (two sided Exact Fisher p < 0.00001). No positives were detected during E. 

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coli O157:H7 follow-up sampling for bench trim or other ground beef components after an E. 

coli positive. 

Sampling beef trim establishments proportional to production volume and requiring that each 

establishment is sampled at least once per year is 1.01 times more likely to detect an E. coli 

O157:H7 positive than under the 2010 MT50 random sampling program. Establishments that supply 

beef trim to raw ground beef establishments that test positive for E. coli O157:H7 are termed beef 

trim suppliers. If it is the only supplier to the ground beef establishment, it is termed a sole beef 

trim supplier. The E. coli percent positives in beef trim suppliers (0.73%) and sole beef trim 

suppliers (0.69%) are not statistically different than that found in the MT50 beef trim sampling 

program (0.60%). The E. coli percent positives in other ground beef component suppliers (0.62%) 

and sole ground beef component suppliers (0.61%), while higher, are not statistically different than 

that found in the MT54 sampling of other ground beef components (0.28%). 

In 2007 FSIS categorized its regulations according to potential public health significance and 

designated those regulations most strongly related to public health as “health-related” 

noncompliances. No predictive relationship was found between health-related regulatory 

noncompliances and the probability of E. coli O157:H7 positive sample results. 

No predictive relationship was found between higher sanitary dressing noncompliances and the 

probability of E. coli O157:H7 positive sample results. In its response to OIG, FSIS proposed to 

revise the sanitary dressing verification Directive 6410.1 with an aim to improve and clarify 

verification of sanitary dressing by FSIS inspectors. This may improve the correlation between 

sanitary dressing noncompliances and E. coli positives in beef trim. There is a definite seasonality in 

E. coli O157:H7 rate in beef trim and beef trim suppliers. The probability of detecting an E. coli 

O157:H7 positive in a beef trim establishment during May-Oct is 3.8 times higher than in the 

rest of the year (two sided Exact Fisher p < 0.002). The probability of a beef trim supplier having 

an E. coli O157:H7 in May-Oct is 1.9 times higher (but not statistically significantly so; two 

sided Exact Fisher p = 0.175) than in the rest of the year. Due to the low number of positives, no 

seasonality is apparent in the number of E. coli positives in bench trim and ground beef components 

other than trim. 

The probability of detecting an E. coli O157:H7 positive in raw ground veal is 19.2 times higher 

than in raw ground beef (this conclusion is based on limited samples in raw ground veal). The E. 

coli percent positive rates in veal trim and beef trim are not statistically significantly different, 

possibly due to the low number of samples in veal trim. 

Of the options reviewed, the ones that appear most promising for increasing the probability of detecting E. 

coli O157:H7 positives during FSIS verification testing are to increase E. coli O157:H7 sampling in 

Volume classes with the highest E. coli O157:H7 percent positive
 

Volume class with the highest volume-weighted E. coli O157:H7 percent positive
 

The six month summer season when E. coli O157:H7 percent positive is highest
 

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Sampling beef trim volume classes in proportion to the E. coli O157:H7 percent positive, ensuring that 

each establishment is sampled at least once per year, and increasing samples during summer months by 

20% increases the probability of detecting an E. coli positive to 2.0 times greater than under the 2010 MT50 

random sampling program. 

Sampling proportional to beef trim volume-weighted percent positive, ensuring that each establishment is 

sampled at least once per year, and increasing samples during summer months by 20% increases the 

probability of detecting an E. coli positive to 1.4 times greater than under the 2010 MT50 random sampling 

program. 

In addition to the above analysis, FSIS assessed over 30 discrete sampling designs and their related 

probabilities to detect E. coli O157:H7 in beef manufacturing trimmings. The design the agency chose 

to implement is weighted, random sampling with replacement that accounts for both the production 

volume and percent positive of volume classes. The agency also chose to over-schedule seasonally 

during the high prevalence season, over-schedule to adjust for non-response, implement an annual 

scheduling floor, and implement monthly scheduling ceilings. The chosen design gives FSIS an 

increased likelihood of 2.5 to detect E. coli O157:H7 as compared to the current design of simple 

random sampling without replacement. 

1.0 INTRODUCTION 

In February 2011 the U.S. Department of Agriculture’s (USDA) Office of Inspector General (OIG) published 

an audit report on the Food Safety Inspection Service (FSIS) sampling protocol for testing beef trim for E. 

coli O157:H7 (OIG 2011). The OIG expressed concerns about the efficacy of the sampling the FSIS 

performs to detect Escherichia coli (E. coli) O157:H7 in U.S. beef trim. OIG recommended that FSIS 

redesign its sampling program to provide a higher degree of confidence that its beef trim tests are 

accurately identifying contaminated product. 

The objective of this report is to evaluate FSIS E. coli O157:H7 sampling designs for testing beef trim, 

bench trim, and raw ground beef components other than trim to evaluate options for increasing the 

degree of confidence for detecting E. coli O157:H7 positives during FSIS verification testing, and to 

document the scientific support and rationale for each of the possible designs. 

E. coli O157:H7 is a bacterium that can cause illness in humans, especially children and older adults. 

Approximately 62,000 cases of symptomatic E. coli O157:H7 infections occur annually in the United 

States due to foodborne exposures, resulting in approximately 1,800 hospitalizations and 52 deaths. 

Surveillance data indicate that the highest incidence of illness from E. coli O157:H7 occurs in children 

under 5 years of age. Ground beef is considered a primary source of human exposure to E. coli O157:H7 

(FSIS 2001). 

Beef trim consists of pieces of meat and fat that remain after cattle carcasses are cut into various intact 

cuts of meat (e.g., loin, ribs, roasts, and steaks). Bench trim is beef trim that is produced during the 

fabrication of primals and sub-primals from cattle not slaughtered on site. Raw ground beef components 

include raw esophagus (weasand) meat, head meat, cheek meat, and other beef components used to 

make raw ground beef. Beef trim, bench trim, and other raw ground beef components are later ground to 

produce ground beef or other hamburger products. 

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E. coli O157:H7 can contaminate beef trim when fecal material from slaughtered cattle comes into 

contact with, and remains on, the carcass. To prevent beef trim from becoming contaminated, plants 

apply interventions—safety controls such as lactic acid sprays, carcass washes, or steam cabinets, which 

are intended to decontaminate carcasses before they are cut into pieces or the meat is shipped from the 

plant. 

The codes for the different domestic products that FSIS currently samples for E. coli O157:H7 are: 

MT43 –Raw ground beef 

MT44 – Follow up testing to a raw ground beef positive
 

MT50 –Beef trim
 

MT52–Supplier of beef trim or other components to raw ground beef establishments with an 

MT43 or MT55 positive
 

MT53 – Follow-up testing of positives from 1) Routine Testing of Beef Trim (MT50); 2) 

Routine Testing of Other Components (MT54); 3) Routine Testing of Bench Trim (MT55); or 4) 

Positive Follow-up Testing at Suppliers (Positive MT52 Samples)
 

MT54 –Components other than trim
 

MT55 – Bench trim (i.e., beef trim derived from cattle not slaughtered in the establishment)
 

The ground beef, beef trim, bench trim, and components other than trim programs were initiated on the
 

following dates.
 

In August 1994, FSIS declared that ground beef containing E. coli O157:H7 to be adulterated 

under the Federal Meat Inspection Act (FMIA) unless further processed in a manner that 

destroys this pathogen. In CY 2010 FSIS analyzed 11,292 raw ground beef samples for E. coli 

O157:H7 and found 26 positives for a percent positive of 0.23%. 

On October 17, 1994, FSIS initiated a microbiological sampling program for E. coli O157:H7 in 

raw ground beef in meat plants and retail stores. 

On March 19, 2007, FSIS began routine verification sampling of beef manufacturing trimmings 

(MT50) intended for use in raw ground beef or beef patty products at the slaughter 

establishments that produced those trimmings. Trimmings that the establishment intends for use 

in further processing into ready-to-eat products are not sampled. The N60 sample collection 

method used to test beef trim in the MT50 sampling program is described in Appendix A. 

On October 26, 2007, FSIS announced the intention to initiate routine verification of other raw 

ground beef components and sampling of those other components began in late December. 

On July 31, 2009 FSIS initiated a bench trim microbiological sampling program for E. coli 

O157:H7 in establishments that produce trim derived from cattle not slaughtered on site (MT55 

Sampling). Establishments that produce beef trimmings from cattle slaughtered on site continue 

to be subjected to sampling under the Trim Verification program (MT50 sampling), and 

establishments that produce other raw ground beef or patty components from cattle slaughtered 

on site continue to be subjected to sampling under the Raw Ground Beef Components program 

(MT54 sampling). 

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2.0 OPTIONS FOR REDESIGN OF FSIS E. COLI O157:H7 SAMPLING 

PROGRAMS 

The purpose of this section is to present options for the redesign of the FSIS E. coli O157:H7 sampling 

programs in beef trim, bench trim, and raw ground beef components other than trim. Each of the options 

will be evaluated in subsequent sections. 

In its response to the OIG report, FSIS states it plans to revise the E. coli MT50 sampling program to focus 

E. coli testing and inspection resources primarily on establishments with the highest probability of producing 

beef trim contaminated with E. coli O157:H7 (FSIS 2011). This will allow FSIS to more effectively verify 

process controls at beef establishments across the nation. FSIS believes that effective verification of food 

safety systems must include inspection of an establishment’s production process to ensure that controls are 

adequately designed and implemented to prevent, eliminate, or reduce contamination with E. coli O157:H7. 

Ten options for focusing E. coli testing primarily on establishments with the highest probability of 

producing beef trim contaminated with E. coli O157:H7 were identified. They are to increase E. coli 

O157:H7 sampling frequency in 

Establishments with E. coli O157:H7 positives 

Volume classes with higher production volumes 

Volume classes with higher E. coli O157:H7 percent positive 

Volume classes with higher volume-weighted E. coli O157:H7 percent positive 

Beef trim and other component supplier establishments associated with E. coli O157:H7 positives in 

raw ground beef 

Establishments with higher HACCP noncompliances 

Establishments with higher sanitary dressing noncompliances 

Seasons of the year with higher E. coli O157:H7 positives 

Geographic regions with higher E. coli O157:H7 percent positive 

Product categories with higher E. coli O157:H7 percent positive 

As a baseline for analysis, the average E. coli O157:H7 positive rates in ground beef, beef trim, bench trim, 

and components other than trim for the years 2007 – June 2011 are presented in the next section. In 

subsequent sections, each of the above options for increasing the probability of detecting E. coli O157:H7 

positives during FSIS verification testing will be evaluated in turn. 

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3.0 AVERAGE E. coli O157:H7 POSITIVE RATES 

This section reviews the FSIS verification testing programs for E. coli O157:H7 in ground beef, beef 

trim, bench trim, and raw ground beef components other than trim and presents the average E. coli 

O157:H7 positive rates for the years 2007-June 2011. 

The intended purpose of ground beef, beef trim, bench trim, and other ground beef component E. coli 

O157:H7 sampling is to verify an establishment’s food safety process control under HACCP. Under 

each program, the establishments tested in any given month are selected at random. Details can be 

found in the Report on the Food Safety and Inspection Service’s Microbiological and Residue Sampling 

Programs (FSIS December 2011). 

3.1 Ground Beef Sampling 

FSIS began routine verification sampling for E. coli O157:H7 in raw ground beef in October 1994. 

There are approximately 1,400 federally inspected establishments producing raw ground beef or raw 

ground beef products that are routinely sampled for E. coli O157:H7 as part of the Agency's HACCP 

verification program. 

Table 3-1 presents the E. coli O157:H7 test results in raw ground beef establishments tested under the 

MT 43 testing program. In CY 2010 FSIS analyzed 11,290 raw ground beef samples for E. coli 

O157:H7 and found 26 positives (0.23%). 

Table 3- 1 E. coli O157:H7 Test Results for Raw Ground Beef 

Year Positives Negatives % Positive 

CY2007 27 11,948 0.23% 

CY2008 48 10,735 0.45% 

CY2009 35 11,537 0.30% 

CY2010 26 11,264 0.23% 

Jan-June 2011 3 5,673 0.05% 

CY2006-June 2011 139 51,157 0.27% 

3.2 Beef Trim 

Currently FSIS collects beef trim samples from about 390 slaughter establishments annually for E. coli 

O157:H7 testing. Approximately 1,300 samples are collected per year, with an average of about seven 

E. coli O157:H7 positives per year resulting in an average E. coli O157:H7 positive rate of 0.60% over 

the period 2007 to June 2011. The average beef trim establishment is sampled about 3.5 times per year. 

Table 3-2 presents the E. coli O157:H7 test results for beef trim establishments tested under the beef 

trim sampling program MT50. During CY 2010, FSIS analyzed 1,274 trim samples for E. coli O157:H7 

from 386 slaughter establishments producing beef trim and found 4 positive samples (0.31 percent). 

There is no statistically significant difference in the E. coli O157:H7 percent positives between years 

(smallest two sided Exact Fisher p = 0.077). The overall E. coli O157:H7 positive rate for the period 

2007-June 2011 is 0.60%. This percent positive is statistically significantly higher (two sided Exact 

Fisher, p < 0.0002) than that found in raw ground beef (0.27%). The probability of detecting an E. coli 

O157:H7 positive in beef trim is 2.2 times higher than in raw ground beef. 

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Table 3- 2 MT50 E. coli O157:H7 Test Results for Beef Trim 

Year 

Number 

Establishments Tested 

Number 

Positives 

Number 

Negatives % Positive 

2007 336 2 710 0.28% 

2008 344 12 1,326 0.90% 

2009 368 9 1,218 0.73% 

2010 386 4 1,270 0.31% 

Jan-June 2011 302 4 597 0.67% 

2007-June 2011 31 5,121 0.60% 

3.3 Bench Trim 

Currently FSIS collects bench trim samples from about 440 processing establishments annually for E. coli 

O157:H7 testing. Approximately 550 samples are collected per year, with an average of about one E. 

coli O157:H7 positive per 2.5 years resulting in an average E. coli O157:H7 positive rate of 0.19% over 

the period 2007 to June 2011. 

Table 3-3 presents the E. coli O157:H7 test results for bench trim establishments tested under the bench 

trim sampling program MT55. There is no statistically significant difference in the E. coli O157:H7 

percent positives between years (smallest two sided Exact Fisher p = 0.214). The overall E. coli 

O157:H7 percent positive for the period 2009-June 2011 is 0.19%. This percent positive is not 

statistically significantly different (Two Tailed Fisher Exact p >0.999) than that found in raw ground 

beef (0.27%) 

Table 3- 3 MT55 E. coli O157:H7 Test Results for Bench Trim 

Year 

Number Establishments 

Tested 

Number 

Positives 

Number 

Negatives % Positive 

2009 149 1 148 0.67% 

2010 440 0 547 0.00% 

Jan-June 2011 266 1 335 0.30% 

2009-June 2011 2 1,030 0.19% 

3.4 Raw Ground Beef Components Other Then Trim 

Currently FSIS collects component samples from about 150 establishments annually from establishments 

producing raw ground beef components other than trim for E. coli O157:H7 testing. Approximately 170 

samples are collected per year, with an average of about two E. coli O157:H7 positives per 3.5 years 

resulting in an average E. coli O157:H7 percent positive of 0.28% over the period 2007 to June 2011. 

Table 3-4 presents the E. coli O157:H7 test results for establishments tested under the MT54 raw ground 

beef components other than trim sampling program. There is no statistically significant difference in the 

E. coli O157:H7 percent positives between years (smallest two sided Exact Fisher p = 1). The overall E. 

coli O157:H7 percent positive for the period 2009-June 2011 is 0.28%. This percent positive is not 

statistically significantly different (two sided Exact Fisher, p >0.723) than that found in raw ground beef 

(0.27%). 

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Table 3- 4 MT54 E. coli O157:H7 Test Results for Ground Beef Components 

Year 

Number 

Establishments 

Tested 

Number 

Positives 

Number 

Negatives 

% 

Positive 

2007 2 0 2 0.00% 

2008 142 1 216 0.46% 

2009 147 1 230 0.43% 

2010 100 0 169 0.00% 

Jan-June 2011 69 0 104 0.00% 

2007-June 2011 2 721 0.28% 

The E. coli O157:H7 percent positive in trim suppliers (0.73%) and sole beef trim suppliers (0.69%) are 

not statistically different than that found in the MT50 beef trim sampling program (0.60%). The E. coli 

percent positives in other ground beef component suppliers (0.62%) and sole ground beef component 

suppliers (0.61%), while higher, are not statistically different than that found in the MT54 sampling of other 

ground beef components (0.28%). 

In summary, the E. coli O157:H7 percent positive in beef trim (0.60%), bench trim (0.19%) and raw 

ground beef components other than trim (0.28%) are not statistically significantly different (smallest two 

sided Exact Fisher, p >0.118). The E. coli O157:H7 percent positive in beef trim (0.60%) is statistically 

significantly higher (two sided Exact Fisher, p < 0.0002) than that found in raw ground beef (0.27%). 

However, the E. coli O157:H7 percent positives in bench trim (0.19%) and raw ground beef components 

other than trim (0.28%) are not statistically significantly different (smallest two sided Exact Fisher, p 

>0.723) than that found in raw ground beef (0.27%). 

The following sections review the options for increasing the probability of detecting E. coli O157:H7 

positives during FSIS verification testing. 

13 
 

 

 

 

 

 

 

 

 

 

4.0 TARGET ESTABLISHMENTS WITH E. COLI O157:H7 POSITIVES
 

The purpose of this section is to determine whether increasing routine trim and components sampling in 

establishments that have an E. coli O157:H7 positive will increase the probability of detecting further E. 

coli positives. 

4.1 E. coli Positive in Routine Testing of Beef Trim (MT50) 

The purpose of this section is to determine if beef trim establishments with an E. coli positive during 

MT50 routine testing have an increased probability of another E. coli positive during routine testing over 

the next 120 days. 

Table 4-1 compares the probability of an MT50 E. coli O157:H7 positive sample result over the 120 

days following an MT50 E. coli O157:H7 positive test result with the probability of an MT50 E. coli 

O157:H7 positive test result over the 120 days following an MT50 E. coli O157:H7 negative test result 

for the years 2007 to June 2011. The difference in the two probabilities is not statistically significant 

(Two sided Fisher Exact, p > 0.138). 

Table 4- 1 Probability of MT50 E. coli Positive in 120 days following an MT50 E. coli Positive 

MT50 E. coli 

Positive Test 

Result in Next 

120 Days 

No MT50 E. coli 

Positive Test 

Result in Next 

120 Days 

Probability of E. coli 

Positive Test Result 

in Next 120 Days 

MT50 E. coli 

Test Result is 

Positive 1 28 3.45% 

MT50 E. coli 

Test Result is 

Negative 27 5,440 0.49% 

4.2 E. coli O157:H7 Positive Follow-Up Sampling 

FSIS currently conducts follow-up E. coli sampling in establishments that have an E. coli positive. The 

follow-up sampling is conducted under the MT53 sampling program. MT53 sampling includes followup testing of positives from 1) routine testing of beef trim (MT50); 2) routine testing of other 

components (MT54); 3) Routine Testing of Bench Trim (MT55); or 4) positive follow-up testing at 

suppliers (positive MT52 samples). Sixteen follow-up samples are scheduled at an establishment with an 

E. coli positive unless the establishment is a low volume producer (less than 1,000 lbs. per day), when 

eight follow-up samples are scheduled. 

Table 4-2 presents the test results for the MT53 E. coli O157:H7 follow-up sampling program for 2008 –

June 2011. There is no statistically significant difference in the E. coli O157:H7 percent positives 

between years (smallest two sided Fisher Exact, p = 0.440). 

The probability of detecting an E. coli O157:H7 positive during MT53 beef trim follow-up sampling are 

6.6 times higher than under MT50 beef trim sampling. No positives were detected during MT53 E. coli 

O157:H7 follow-up sampling for bench trim or other components. 

14 
 

 

 

Table 4- 2 MT53 Follow-Up Test Results for Beef Trim 

Year 

# Plants # Plants with 

Positives in 

follow-up Positives Negatives % Positive 

2008 12 1 3 122 2.40% 

2009 12 3 7 158 4.24% 

2010 12 1 5 120 4.00% 

Jan-June 2011 8 2 4 79 4.82% 

2008-June 2011 44 7 19 479 3.82% 

Table 4-3 and Table 4-4 presents follow-up test results for bench trim and raw ground beef components 

other than trim. 

Table 4- 3 MT53 Follow-Up Test Results for Bench Trim 

Year 

# Plants # Plants with 

Positives in 

follow-up Positives Negatives % Positive 

2008 0 0 0 0 0.00% 

2009 1 0 0 16 0.00% 

2010 0 0 0 0 0.00% 

Jan-June 2011 1 0 0 8 0.00% 

2008-June 2011 2 0 0 24 0.00% 

Table 4- 4 MT53 Follow-Up Test Results for Other Components 

Year 

# Plants # Plants with 

Positives in 

follow-up Positives Negatives % Positive 

2008 1 0 0 16 0.00% 

2009 0 0 0 0 0.00% 

2010 0 0 0 0 0.00% 

Jan-June 2011 0 0 0 0 0.00% 

2008-June 2011 1 0 0 16 0.00% 

Conclusion: These results demonstrate that increasing E. coli O157:H7 sampling after an E. coli 

positive in beef trim is an effective means of increasing the probability of detecting an E. coli positive in 

beef trim. However, FSIS under the MT53 sampling program already increases E. coli O157:H7 

sampling after an E. coli positive in beef trim. Thus this option is already being implemented as a means 

of increasing the probability of detecting E. coli O157:H7 positives in beef trim. 

Follow up testing in bench trim and raw ground beef components other than trim has not produced an 

increase in the probability of detecting an E. coli O157:H7 positive. Thus, while follow up testing for 

bench time and raw ground beef components other than trim should be continued, there does not seem to 

be evidence for increasing the number of samples taken. 

15 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

5.0 TARGET VOLUME CLASSES WITH LARGER VOLUMES
 

The purpose of this section is to determine whether allocating the number of samples in each volume 

class in proportion to the volume of that volume class will increase the probability of detecting E. coli 

positives. Under this option, the volume classes with the largest volume would be tested more frequently. 

5.1 E. coli O157:H7 Percent Positive for Different Volume Classes 

Table 5-1 presents the E. coli test results as a function of beef trim volume class for the years CY2007 

through June 2011 combined (See Appendix B for more detail on the relationship between beef trim 

volumes and E. coli positives). The data were combined since no statistically significant difference was 

found in the E. coli O157:H7 positive rates in the years CY2007 through June 2011 (see Section 3.1). In 

addition, combining the data produces a larger number of samples for each trim volume class and thus 

produces more accurate estimates of the percent positive for the volume classes. A total of 509 unique 

beef trim establishments were tested during the period 2007-June 2011. However, because some 

establishments change volume class from year to year, the total number of unique establishments in 

Table 5-1 is 582. 

Table 5- 1 Volume Classes for Beef Trim MT50 E. coli O157:H7 Sampling for 2007-June 2011 

Volume Class 

# of unique 

plants 

Total volume 

CY2007-June 

2011 (pounds) 

% of 

Total 

Volume 

E. coli 

Positives 

Total 

Tests 

% 

Positive 

Very Small 408 95,025,000 0.49% 15 3,558 0.42% 

Small 93 1,268,625,000 6.48% 9 612 1.47% 

Medium 41 4,725,000,000 24.12% 5 452 1.11% 

Large 40 13,500,000,000 68.92% 2 530 0.38% 

Total 582 19,588,650,000 100.00% 31 5,152 0.60% 

The large volume class has the smallest E. coli percent positive, while the small volume class has the 

highest E. coli percent positive. There is no statistically significant difference in the E. coli O157:H7 

percent positive for any of the volume classes (Smallest Two sided Fisher Exact p > 0.066) except for 

very small class, where the E. coli O157:H7 is statistically significantly less than that of the small beef 

trim volume classes (Two sided Fisher Exact p = 0.005) . 

Sampling beef trim establishments proportional to production volume and requiring that each establishment 

is sampled at least once per year is only slightly more likely (1.01) to detect an E. coli O157:H7 positive; 

however, it does make sampling more representative of national production (See Appendix C). 

Table 5-2 and Table 5-3 present the E. coli test results as a function of bench trim and other raw ground 

beef components production volume respectively for the years CY2007 through June 2011 combined. 

Again, the smaller volume classes have the highest E. coli percent positives, while the larger volume 

classes have zero percent positive. 

16 
 

 

 

 

 

 

 

 

 

 

Table 5- 2 Volume Classes for Bench Trim MT55 E. coli O157:H7 Sampling for 2009- June 2011 

Volume Class 

# of unique 

plants 

E. coli 

Positives 

Total 

Tests % Positive 

Very Small 353 1 552 0.18% 

Small 77 1 124 0.81% 

Medium 131 0 154 0.00% 

Large 183 0 202 0.00% 

Total 744 2 1,032 0.19% 

Table 5- 3 Volume Classes for Other Ground Beef Components MT54 E. coli O157:H7 Sampling 

for 2008-June 2011 

Volume Class 

# of unique 

plants 

E. coli 

Positives 

Total 

Tests % Positive 

Very Small 206 1 462 0.22% 

Small 67 1 156 0.64% 

Medium 21 0 42 0.00% 

Large 17 0 63 0.00% 

Total 311 2 723 0.28% 

Conclusion: These results demonstrate that beef trim, bench trim, and other ground beef component 

establishments have the lowest E. coli percent positive rates in the large volume class and the highest E. 

coli percent positive rates in the small production volume class. MT50 sampling in the small trim 

volume class has a 2 times higher probability of detecting an E. coli O157:H7 positive than MT50 

sampling in large trim volume establishments. 

These results demonstrate that increasing E. coli O157:H7 sampling in proportion to the relative volume 

of the volume class may not provide an effective means of increasing the probability of detecting an E. 

coli positive in beef trim, bench trim, and other ground beef component establishments. In fact, 

sampling proportional to production volume in beef trim establishments and requiring that each 

establishment is sampled at least once per year is only slightly more likely (1.01) to detect an E. coli 

O157:H7 positive than the 2010 random sampling program (See Appendix C). 

17 
 

 

 

 

 

 

 

 

6.0 TARGET VOLUME CLASSES WITH LARGER E. coli PERCENT 

POSITIVE 

The purpose of this section is to determine whether allocating sampling for a volume class in proportion 

to the E. coli O157:H7 percent positive for that volume class will increase the probability of detecting E. 

coli positives. Under this option, the volume classes with the highest E. coli percent positive would 

receive the largest number of samples. The rationale for this option is that it targets volume classes that 

are most likely to have an E. coli O157:H7 positive. 

Table 6-1 shows the average number of samples per beef trim plant if sampling were proportional to the 

percent positive in each volume class based on CY2010 data. Sampling volume classes proportional to 

percent positive in the volume class is 1.9 times more likely to detect an E. coli O157:H7 positive than under 

the current MT50 random sampling program (See Appendix C). Sampling volume classes proportional to 

percent positive in the volume class and requiring that each establishment is sampled at least once is 1.8 

times more likely to detect an E. coli O157:H7 positive than under the current MT50 random sampling 

program (see Appendix C). 

Table 6- 1 Distribution of Samples per Beef Trim Plant if Sampling Proportional to Percent 

Positive 

Volume 

Class 

2010 

Unique 

Plants 

2010 

Total 

Tests 

2010 

Average 

Tests per 

Plant 

MultiYear % 

Positive 

Number of 

Samples if 

proportional to 

% Positive 

Average Tests 

per Plant if 

Proportional to 

% Positive 

Very Small 291 915 3.1 0.42% 158 0.5 

Small 42 136 3.2 1.47% 554 13.2 

Medium 25 93 3.7 1.11% 418 16.7 

Large 28 130 4.6 0.38% 143 5.1 

Total 386 1,274 3.3 0.60% 1,274 3.3 

Table 6-2 shows the average number of samples per bench trim plant if sampling were proportional to 

the percent positive in each volume class based on number of samples taken in CY2010. Sampling 

volume classes proportional to percent positive in the volume class is 3.6 times more likely to detect an E. 

coli O157:H7 positive than under the current MT55 random sampling program. However, under this 

sampling design, no samples would be taken in some volume classes. Sampling volume classes proportional 

to percent positive in the volume class and requiring that each establishment is sampled at least once is 2.5 

times more likely to detect an E. coli O157:H7 positive than under the current MT55 random sampling 

program (Calculated similar to examples in Appendix C). 

18 
 

 

 

 

 

Table 6- 2 Distribution of Samples per Bench Trim Plant if Sampling Proportional to Percent 

Positive 

Volume 

Class 

2010 

Unique 

Plants 

2010 

Total 

Tests 

2010 

Average 

Tests per 

Plant 

MultiYear % 

Positive 

Number of 

Samples if 

proportional to 

% Positive 

Average Tests 

per Plant if 

Proportional to 

% Positive 

Very Small 222 274 1.2 0.18% 99 0.4 

Small 52 69 1.3 0.81% 448 8.6 

Medium 77 98 1.3 0.00% 0 0.0 

Large 89 106 1.2 0.00% 0 0.0 

Total 440 547 1.2 0.19% 547 1.2 

Table 6-3 shows the average number of samples per other ground beef component plant if sampling 

were proportional to the percent positive in each volume class based on number of samples taken in 

CY2010. Sampling volume classes proportional to percent positive in the volume class is 2.0 times more 

likely to detect an E. coli O157:H7 positive than under the current MT54 random sampling program. 

However, under this sampling design, no samples would be taken in some volume classes. Sampling volume 

classes proportional to percent positive in the volume class and requiring that each establishment is sampled 

at least once is 1.9 times more likely to detect an E. coli O157:H7 positive than under the current MT54 

random sampling program (Calculated similar to examples in Appendix C). 

Table 6- 3 Distribution of Samples per Other Ground Beef Component Plant if Sampling 

Proportional to Percent Positive 

Volume 

Class 

2010 

Unique 

Plants 

2010 

Total 

Tests 

2010 

Average 

Tests per 

Plant 

MultiYear % 

Positive 

Number of 

Samples if 

proportional to 

% Positive 

Average Tests 

per Plant if 

Proportional to 

% Positive 

Very Small 67 101 1.5 0.22% 43 0.6 

Small 24 37 1.5 0.64% 126 5.2 

Medium 4 8 2.0 0.00% 0 0.0 

Large 5 23 4.5 0.00% 0 0.0 

Total 100 169 1.7 0.28% 169 1.7 

Conclusion: 

These results demonstrate that sampling volume classes in proportion to the percent positive of the volume 

class will increase the probability of detecting an E. coli O157:H7 percent positive. 

19 
 

 

 

 

 

 

 

 

 

7.0 TARGET VOLUME CLASSES WITH LARGER VOLUME-WEIGHTED 

PERCENT POSITIVE 

One option for improving the MT50 sampling program is to make sampling in each volume class 

proportional to the volume-weighted percent positive of the volume class. The volume-weighted percent 

positive for a volume class is the product of its E. coli percent positive with the fraction of total production 

volume in that volume class (see Appendix B for more detail). Under such a program, production categories 

with higher volume-weighted percent positives would be tested more frequently. The rational for volumeweighted sampling is that it decreases the uncertainty in the E. coli percent positive estimate for the largest 

volume class and therefore provides the best approximation to the prevalence of E. coli O157:H7 in the beef 

trim supply. This option differs from the previous option (sampling proportional to percent positive) in that 

it targets volume classes that are most likely to cause the most number of illnesses as opposed to the previous 

option which targets volume classes most likely to have an E. coli O157:H7 positive. 

Table 7-1 presents an estimate of the beef trim volume-weighted percent positive for E. coli O157:H7 

based on cumulative data for the years CY2007 through June 2011. The volume-weighted percent 

positive over these years is 0.63%. Sampling volume classes proportional to volume-weighted percent 

positive in the volume class is 1.5 times more likely to detect an E. coli O157:H7 positive than under the 

current MT50 random sampling program. 

Table 7- 1 E. coli O157:H7 Beef Trim Volume-Weighted Percent Positive 

Volume 

Class 

Number 

Estabs 

Tested 

Total volume 

CY2007-June 

2011 (pounds) 

% of 

Total 

Volume 

Number 

Samples 

% of 

Total 

Samples 

Unweighted 

% Positive 

Volume 

Weighted 

% 

Positive 

Very 

Small 1,267 95,025,000 0.49% 3,558 69.06% 0.42% 0.00% 

Small 199 1,268,625,000 6.48% 612 11.88% 1.47% 0.10% 

Medium 126 4,725,000,000 24.12% 452 8.77% 1.11% 0.27% 

Large 144 13,500,000,000 68.92% 530 10.29% 0.38% 0.26% 

Total 1,736 19,588,650,000 100.00% 5,152 100.00% 0.60% 0.63% 

Table 7-2 shows the average number of samples per beef trim plant if sampling were proportional to the 

volume-weighted percent positive in each volume class based on CY2010 data. Sampling beef trim 

volume classes proportional to volume-weighted percent positive is 1.5 times more likely to detect an E. coli 

O157:H7 positive than under the current MT50 random sampling program (See Appendix C). Sampling beef 

trim volume classes proportional to volume-weighted percent positive and requiring that each establishment 

is sampled at least once is 1.3 times more likely to detect an E. coli O157:H7 positive than under the current 

MT50 random sampling program (See Appendix C). 

20 
 

 

 

 

 

Table 7- 2 Distribution of Samples per Beef Trim Plant if Sampling Proportional to Volume 

Weighted Percent Positive 

Volume 

Class 

# of 

unique 

plants 

2010 # 

of 

Samples 

2010 

Average 

Tests 

per 

Plant 

Volume 

Weighted 

% Positive 

Distribution 

of Volume 

Weighted 

Percent 

Positives 

Number of 

Samples if 

proportional 

to volume 

weighted % 

Positive 

Average 

Tests per 

Plant if 

Proportional 

to volume 

weighted % 

Positive 

Very Small 291 915 3.1 0.00% 0.38% 5 0.0 

Small 42 136 3.2 0.10% 16.12% 205 4.9 

Medium 25 93 3.7 0.27% 42.63% 543 21.7 

Large 28 130 4.6 0.26% 40.87% 521 18.6 

Total 386 1,274 3.3 0.63% 100.00% 1,274 3.3 

Table 7-3 presents an estimate of the volume-weighted percent positive for E. coli O157:H7 in bench 

trim based on cumulative data for the years CY2009 through June 2011. The volume-weighted percent 

positive for bench trim over these years is 0.02%. Sampling bench trim volume classes proportional to 

volume-weighted percent positive in the volume class is 4.1 times more likely to detect an E. coli O157:H7 

positive than under the current MT55 random sampling program. 

Table 7- 3 E. coli O157:H7 Bench Trim Volume-Weighted Percent Positive 

Volume 

Class 

Number 

Estabs 

Tested 

Total volume 

CY2007-June 

2011 (pounds) 

% of 

Total 

Volume 

Number 

Samples 

% of 

Total 

Samples 

Unweighted 

% Positive 

Weighted 

% 

Positive 

Very 

Small 445 33,375,000 0.15% 552 53.49% 0.18% 0.00% 

Small 93 592,875,000 2.59% 124 12.02% 0.81% 0.02% 

Medium 132 4,950,000,000 21.60% 154 14.92% 0.00% 0.00% 

Large 185 17,343,750,000 75.67% 202 19.57% 0.00% 0.00% 

Total 855 22,920,000,000 100.00% 1,032 100.00% 0.19% 0.02% 

Table 7-4 presents estimates of the volume-weighted percent positive for E. coli O157:H7 in ground 

beef components other than trim based on cumulative data for the years CY2009 through June 2011. 

The volume-weighted percent positive for ground beef components other than trim over these years is 

0.1%. Sampling raw ground beef component volume classes proportional to volume-weighted percent 

positive in the volume class is 2.3 times more likely to detect an E. coli O157:H7 positive than under the 

2010 MT54 random sampling program. 

21 
Table 7- 4 E. coli O157:H7 Other Component Volume-Weighted Percent Positive 

Trim 

Volume 

Class 

Number 

Estabs 

Tested 

Trim volume 

CY2007-June 

2011 (pounds) 

% of 

Total 

Volume 

Number 

Samples 

% of 

Total 

Samples 

Unweighted 

% Positive 

Weighted 

% 

Positive 

Very 

Small 310 23,250,000 0.60% 462 63.90% 0.22% 0.00% 

Small 100 637,500,000 16.41% 156 21.58% 0.64% 0.10% 

Medium 26 975,000,000 25.09% 42 5.81% 0.00% 0.00% 

Large 24 2,250,000,000 57.90% 63 8.71% 0.00% 0.00% 

Total 460 3,885,750,000 100.00% 723 100.00% 0.28% 0.11% 

Conclusion: These results demonstrate that sampling volume classes in proportion to the volume-weighted 

percent positive of the volume class will increase the probability of detecting an E. coli O157:H7 percent 

positive. 

22 
 

 

 

 

 

 

 

 

 

 

8.0 TARGET ESTABLISHMENTS ASSOCIATED WITH E. COLI POSITIVES 

IN RAW GROUND BEEF 

Slaughter establishments that supply beef trim, bench trim, or other components to raw ground beef 

establishments that test positive for E. coli O157:H7 are sampled under the MT52 sampling program. 

MT52 sampling is performed in supplier slaughter establishments following a raw ground beef (MT43 

sampling) positive, a positive in follow-up sampling in response to a raw ground beef positive (MT44 

sampling), or a positive sample from bench trim (MT55 sampling). MT52 samples are also taken for the 

Agricultural Marketing Service (AMS) School Lunch Program and of suppliers, when raw ground beef 

or bench trim are recalled. For the purposes of this report slaughter establishments tested under the MT 

52 sampling program will be called supplier establishments or simply suppliers. A beef trim or other 

component supplier that is the only establishment that supplied beef trim or other components to a raw 

ground beef establishment that tested positive for E. coli O157:H7 will be called a sole supplier. 

Supplier establishments are identified by FSIS traceback to the originating slaughter establishments and 

are documented and tracked in the Supplier Traceback to E. coli Positive System (STEPS). Sixteen 

follow up samples are scheduled at a sole supplier establishment unless the establishment is a low 

volume producer (less than 1,000 lbs. per day), when eight follow up samples are collected. One follow 

up sample is collected at supplier establishments that are not sole suppliers unless they are identified in 

STEPS more than once in the past 120 days. 

Table 8-1 shows the MT52 program E. coli O157:H7 test results for CY2007 through June CY2011. An 

average of 49 supplier establishments were identified and tested annually for the years CY2007­

CY2010. Over the period CY2007-June 2011, 110 unique supplier establishments were identified and 

tested for E. coli O157:H7. There is no statistically significant difference in the E. coli O157:H7 percent 

positives for the years 2007 – 2010 (smallest two sided Exact Fisher p > 0.579). 

Table 8- 1 MT52 E. coli O157:H7 Test Results for Suppliers 

Year 

Number Supplier 

Estabs 

Number 

Positives 

Total 

Tests % Positive 

2007 47 1 266 0.38% 

2008 40 4 623 0.64% 

2009 63 9 940 0.96% 

2010 46 4 636 0.63% 

Jan-June 2011 12 1 181 0.55% 

2007-June 2011 208 19 2,646 0.72% 

The E. coli percent positive in suppliers (0.72%) in Table 8-1 is not statistically different than that found 

in the MT50 beef trim sampling program (0.60%) in Table 3-1 (two-tailed corrected Chi Square p = 

0.64, uncorrected Pearson Chi Square p = 0.54). 

Table 8-2 separates suppliers into beef trim suppliers and other suppliers. The other supplier category 

consists almost entirely of suppliers of other ground beef components. The E. coli percent positive in 

beef trim suppliers (0.73%) in Table 8-2 is not statistically different than that found in the other 

suppliers (0.69%) (two sided Exact Fisher = 1). 

23 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

Table 8- 2 MT52 E. coli O157:H7 Test Results for Beef Trim and Other Suppliers 

Beef Trim Suppliers Other Suppliers 

Year Positive Total Tests Rate Positive Total Tests Rate 

2007 1 242 0.41% 0 24 0.00% 

2008 3 499 0.60% 1 124 0.81% 

2009 8 708 1.13% 1 232 0.43% 

2010 2 349 0.57% 2 287 0.70% 

Jan-June 2011 0 125 0.00% 1 56 1.79% 

2007-June 2011 14 1,923 0.73% 5 723 0.69% 

Table 8-3 shows the MT52 program E. coli O157:H7 testing results for all sole supplier establishments 

for CY2007 through June CY2011. On average, 33 supplier establishments are identified as sole 

suppliers per year for the years CY2007-CY2010. There is no statistically significant difference in the E. 

coli O157:H7 percent positives for the years 2007 – June 2011 between the supplier E. coli percent 

positive rate in Table 8-1 (0.73%) and that for sole suppliers in Table 8-3 (0.62%) (Two sided Exact 

Fisher p = 0.703). 

Table 8- 3 MT52 E. coli O157:H7 Test Results for Sole Suppliers 

Year 

Number Sole 

Suppliers 

Number 

Positives 

Total 

Tests % Positive 

2007 30 1 210 0.48% 

2008 30 4 477 0.84% 

2009 39 6 795 0.75% 

2010 32 2 486 0.41% 

Jan-June 2011 7 0 130 0.00% 

2007-June 2011 138 13 2,098 0.62% 

Table 8-4 separates sole suppliers into sole beef trim suppliers and other sole suppliers. The other sole 

supplier category consists almost entirely of sole suppliers of other ground beef components. 

Table 8- 4 MT52 E. coli O157:H7 Test Results for Sole Beef Trim and Other Sole Suppliers 

Sole Beef Trim Suppliers Other Sole Suppliers 

Year Positive Total Tests Rate Positive Total Tests Rate 

2007 1 191 0.52% 0 19 0.00% 

2008 3 415 0.72% 1 62 1.61% 

2009 5 607 0.82% 1 188 0.53% 

2010 1 319 0.31% 1 167 0.60% 

Jan-June 2011 0 78 0.00% 0 52 0.00% 

2007-June 2011 10 1,610 0.62% 3 488 0.61% 

The E. coli percent positive in sole suppliers (0.62%) in Table 8-3 is not statistically different than that 

found in sole beef trim suppliers (0.62%) (Two sided Exact Fisher p = 1) or in other sole suppliers 

(0.61%) (Two sided Exact Fisher p = 1) from Table 8-4. 

24 
 

 

 

 

Volume estimates are not collected under the MT52 suppler sampling program. Therefore, E. coli 

percent positives for suppliers are not presented as a function of volume class. 

Conclusion: There is no statistically significant difference between the E. coli O157:H7 positive rates in 

MT50 sampling of beef trim (0.60%), MT52 sampling of beef trim suppliers (0.72%), and MT52 

sampling of sole beef trim suppliers (0.62%). There is also no statistically significant difference 

between the E. coli O157:H7 positive rates in MT54 sampling of other ground beef components 

(0.28%), MT52 sampling of other suppliers (0.69%), and MT52 sampling of other sole suppliers 

(0.61%). 

FSIS under the MT52 sampling program already increases E. coli O157:H7 sampling in slaughter 

establishments associated with an E. coli positive in raw ground beef. Thus this option is already being 

implemented as a means of increasing the probability of detecting E. coli O157:H7 positives in slaughter 

establishments that are associated with an E. coli O157:H7 positive in raw ground beef. 

25 
 

 

 

 

 

 

9.0 TARGET ESTABLISHMENTS WITH HIGHER HACCP NONCOMPLIANCES 

This section reviews the health-related regulatory noncompliance record (NR) for (1) slaughter 

establishments that produce beef trim and (2) supplier establishments that supplied beef trim to raw ground 

beef establishments that tested positive for E. coli O157:H7. 

FSIS inspection program personnel perform inspection procedures in federally-inspected establishments 

each day to verify that the establishments are executing their SSOP and HACCP system under 9 CFR 

416 and 417. In 2007 FSIS categorized its regulations according to potential public health significance 

and designated those regulations most strongly related to public health as “health-related” 

noncompliances. The rate at which an establishment fails to meet these health-related requirements and 

receives a health-related noncompliance is considered by FSIS to be an indication of the establishment’s

inability to control its production process and risk. 

Ten inspection procedures are utilized by FSIS inspectors in all slaughter establishments. They are 

01A01, 01B01, 01B02, 01C01, 01C02, 03A01, 03J01, 03J02, 05A01 and 06D01 (See Appendix D for 

definition of each procedure code). The number of inspection procedures performed and the number of 

health-related NRs issued were determined for each procedure code for each of the years CY2007 to 

June 2011 for each slaughter establishment producing beef trim. Noncompliances for the occurrence of 

fecal material on beef carcasses were also evaluated. 

All ten inspection procedures were evaluated, but only 03J02 (03J02 consists of verifying all HACCP 

requirements at all critical control points in the HACCP slaughter establishment) was found to have 

statistically significantly higher health-related noncompliances for establishments with E. coli O157:H7 

positives (Two sided Exact Fisher p = 0.005). The inspection procedure 03J01 (03J01 consists of verifying 

one or more HACCP requirements for monitoring, verification, and recordkeeping at a slaughter 

establishment) was not statistically significantly higher (Two sided exact fisher p = 0.116) for beef trim 

establishments with an E. coli positive. There was no difference in the rate of fecal noncompliances. 

9.1 Beef Trim Establishments 

Table 9-1 presents the 03J01 and 03J02 health-related noncompliance rates for beef trim establishments with 

and without E. coli O157:H7 positives during beef trim MT50 sampling. 

Table 9- 1 Health-Related Noncompliance Rates for Beef Trim Establishments With and Without 

E. coli O157:H7 Positives during MT50 Sampling 

03J01 03J02 

Year 

With E. coli 

Positive 

Without E. coli 

Positive 

With E. coli 

Positive 

Without E. coli 

Positive 

CY2007 0.00% 0.76% 0.64% 0.53% 

CY2008 0.00% 0.69% 0.09% 0.48% 

CY2009 0.55% 0.40% 0.13% 0.41% 

CY2010 2.18%* 0.38% 5.74%* 0.62% 

Jan-June 2011 1.4% 0.47% 0.00% 0.63% 

CY2007-June 2011 0.77% 0.53% 0.97%* 0.52% 

*Indicates statistically significant difference (two sided Exact Fisher p < 0.01 for both 03J01 and 03J02). . 

All other entries are not statistically significantly different. 

26 
 

 

 

 

 

 

 

 

 

The results in Table 9-1 are annual health-related noncompliances. It is expected that beef trim establishment 

03J01 and 03J02 health-related noncompliances in the 3 or 6 months preceding an E. coli positive in beef 

trim may be higher than those 9 to 12 months before the E. coli positive. Table 9-2 presents 03J01 and 03J02 

health-related noncompliance rates in 3 month increments for the months preceding an E. coli positive in 

beef trim based on 2007-June 2011 cumulative data. 

Table 9- 2 Beef Trim Establishment 03J01 and 03J02 Health-Related Non-compliances in the 

Months Preceding an E. coli Positive in Beef Trim 

During the 3 

months 

before the E. 

coli positive 

Between 6 

and 3 months 

before E. coli 

positive 

Between 9 

and 6 months 

before E. coli 

positive 

Between 12 

and 9 months 

before E. coli 

positive 

03J01 0.71% 0.17% 0.53% 0.84% 

03J02 1.36% 0.45% 1.92% 0.15% 

The 03J01health-related noncompliance rate of 0.71% in the 3 months before an E. coli positive (in trim 

establishments with an E. coli positive between 2007 and June 2011) is not statistically different than the 

average E. coli noncompliance rate of 0.53% for trim establishments without an E. coli positive in Table 9-1 

(Two sided Exact Fisher p = 1). 

The 03J02 health-related noncompliance rate of 1.36% in the 3 months before an E. coli positive (in trim 

establishments with an E. coli positive between 2007 and June 2011) is statistically greater (Two sided Exact 

Fisher = 0.0058) than the average E. coli noncompliance rate of 0.52% for trim establishments without an E. 

coli positive in Table 9-1. This suggests that there is a correlation between 03J02 non-compliance and E. coli 

positives, but further investigation is necessary to show that a 03J02 non-compliance is likely to predict a 

future E. coli positive. 

Table 9-3 shows that in the 3 months following a 03J02 non-compliance, beef trim establishments are more 

likely, but not statistically significantly so, (two sided Exact Fisher p = 0.0846) to have an E. coli positive 

than in the 3 months following a compliant 03J02. This demonstrates that a noncompliant 03J02 is not 

predictive of an E. coli positive in the following 3 months. 

Table 9- 3 Probability Beef Trim Establishment Has an E. coli Positive in 3 Months Following an 

03J02 Inspection 

Number of samples 

that were E. coli 

Positive 

Number of samples 

that were not E. coli 

Positive 

E. coli 

percent 

positive 

MT50 Samples Taken up to 3 

Months after a noncompliant 

03J02 5 357 1.38% 

MT50 Samples Taken up to 3 

months after a compliant 03J02 724 112,890 0.64% 

9.2 Beef Trim Suppliers 

Table 9-4 presents 03J01 and 03J02 health-related noncompliance rates for beef trim suppliers. For the 

period 2007-June 2011, the 03J01 and 03J02 health-related noncompliance rates for beef trim suppliers are 

statistically significantly higher (Two sided Exact Fisher p < 0.0001) than 03J01 or 03J02 rates for beef trim 

establishments without E. coli positives from Table 9-1. For the period 2007-June 2011, the odds ratio 

associated with the 03J01 non-compliance rates is 2.2 with a confidence interval of 1.9 to 2.5. The odds ratio 

associated with the 03J02 non-compliance rates is 2.1 with a confidence interval of 1.8 to 2.4. This means 

27 
 

 

 

 

 

that a beef trim suppler is about 2 times more likely to have a 03J01 or 03J02 health-related noncompliance 

than a beef trim establishment without an E. coli positive. 

Table 9- 4 03J01 and 03J02 Health-Related Noncompliance Rates for Beef Trim Suppliers 

03J01 03J02 

Year Noncompliant Compliant Rate Noncompliant Compliant Rate 

CY2007 51 4,120 1.22%* 33 4,319 0.76% 

CY2008 118 5,141 2.24%* 69 4,715 1.44%* 

CY2009 34 6,893 0.49% 47 6,479 0.72%* 

CY2010 34 6,893 0.49% 83 5,592 1.46%* 

Jan-June 2011 4 747 0.53% 0 581 0.00% 

CY2007-June 2011 262 22,569 1.15%* 232 21,686 1.06%* 

*Indicates statistically significantly higher than 03J01 or 03J02 rates for beef trim establishments without E. 

coli positives from Table 9-1. All other entries are not statistically significantly different 

Table 9-5 shows that in the 3 months following a 03J01 non-compliance, beef trim supplier establishments 

are less likely but not statistically significantly so (two sided Exact Fisher p = 0.380), to have an E. coli 

positive than in the 3 months following a compliant 03J01 inspection. The lack of statistical significance 

supports the conclusion that a 03J01 noncompliance is not predictive of an E. coli O157:H7 positive in the 

near future. 

Table 9- 5 Probability Beef Trim Supplier Has an E. coli Positive in 3 Months Following an 03J01 

Inspection 

Number of 

Samples that were 

E. coli Positive 

Number of Samples 

that were not E. 

coli Positive 

E. coli 

Percent 

Positive Rate 

MT50 Samples in Beef Trim Suppliers Taken 

within 3 Months following a noncompliant 03J01 1 275 0.36% 

MT50 Samples in Beef Trim Suppliers Taken 

within 3 Months following a compliant 03J01 427 38,657 1.09% 

Table 9-6 shows that in the 3 months following a 03J02 non-compliance, beef trim supplier establishments 

are more likely but not statistically significantly so (two sided Exact Fisher p = 0.348), to have an E. coli 

positive than in the 3 months following a compliant 03J02 inspection. The lack of statistical significance 

supports the conclusion that a 03J02 noncompliance is not predictive of an E. coli O157:H7 positive in the 

near future. 

Table 9- 6 Probability Beef Trim Supplier Has an E. coli Positive in 3 Months Following an 03J02 

Inspection 

Number of 

Samples that were 

E. coli Positive 

Number of Samples 

that were not E. 

coli Positive 

E. coli 

Percent 

Positive Rate 

MT50 Samples in Beef Trim Suppliers Taken 

within 3 Months following a noncompliant 03J02 4 245 1.61% 

MT50 Samples in Beef Trim Suppliers Taken 

within 3 Months following a compliant 03J02 410 36,873 1.10% 

28 
 

 

 

Table 9-7 presents the 03J01 and 03J02 health-related noncompliance rates for beef trim establishments that 

were not suppliers. 

Table 9- 7 03J01 and 03J02 Health-Related Noncompliance Rates for Beef Trim Establishments 

That Are Not Suppliers 

Beef Trim that are 

not Suppliers 03J01 

03J02 

Year Noncompliant Compliant Rate Noncompliant Compliant Rate 

CY2007 115 17,751 0.64% 84 17,884 0.47% 

CY2008 81 23,403 0.34% 74 24,954 0.30% 

CY2009 91 23,851 0.38% 82 25,459 0.32% 

CY2010 82 27,786 0.29% 141 27,239 0.51% 

Jan-June 2011 56 11,159 0.50% 72 10,938 0.65% 

CY2007-June 2011 425 103,950 0.41% 453 106,474 0.42% 

Table 9-8 presents a comparison between the 03J01 and 03J02 health-related noncompliance rates for beef 

trim suppliers and beef trim establishments that were not suppliers. Both the 03J01 and 03J02 health-related 

noncompliances are statistically significantly higher for beef trim suppliers than non-suppliers (two sided 

Exact Fisher p < 0.0001 for both 03J01 and 03J02). 

For the period 2007-June 2011, the odds of a beef trim supplier having a 03J01 non-compliance is 1.3 times 

higher (confidence interval of 1.2 to 1.5) than a beef trim non-supplier having a 03J01 noncompliance. The 

odds ratio associated with the 03J02 non-compliance rates is 1.3 with a confidence interval of 1.1 to 1.4. 

Thus, beef trim suppliers are about 1.3 times more likely to have a 03J01 or 03J02 health-related 

noncompliance than a beef trim non-supplier. 

Table 9- 8 03J01 and 03J02 Health-Related Noncompliance Rates for Beef Trim Suppliers and 

Non-Suppliers 

03J01 03J02 

Year Supplier Not Supplier Supplier Not Supplier 

CY2007 1.22% 0.64%* 0.76% 0.47%* 

CY2008 2.24% 0.34%* 1.44% 0.30%* 

CY2009 0.49% 0.38% 0.72% 0.32%* 

CY2010 0.96% 0.29%* 1.46% 0.51%* 

Jan-June 2011 0.53% 0.50% 0.00% 0.65% 

CY2007-June 2011 1.15% 0.41%* 1.06% 0.42%* 

*Indicates statistically significant difference. All other entries are not statistically significantly different. 

Conclusion: No predictive relationship was found between health-related regulatory noncompliances and 

the probability of E. coli O157:H7 positive sample results. 

29 
 

 

10.0 TARGET ESTABLISHMENTS WITH SANITARY DRESSING NONCOMPLIANCES 

FSIS in its response to OIG suggested that sanitary dressing noncompliances (06D01) may be related to E. 

coli O157:H7 positives in beef trim since carcass contamination is the primary cause of ground beef 

component adulteration with E. coli O157:H7 (FSIS 2011). The review of regulatory noncompliances in 

Section 5 found no statistically significant differences in the 06D01 health-related noncompliance rates 

between beef trim establishments with and without E. coli positives. In fact, the 31 beef trim establishments 

with E. coli positives did not have any 06D01 noncompliances during the period 2007 – June 2011, while the 

478 beef trim establishments without E. coli positives had 3 06D01 noncompliances. 

There was also no statistically significant difference in the carcass fecal contamination NR rates (Regulation 

code 381.65(e)) between beef trim establishments with and without E. coli positives. The 31 beef trim 

establishments with E. coli positives had one carcass fecal noncompliance during the period 2007 – June 

2011, while the 478 beef trim establishments without E. coli positives had 31. 

Conclusion: It does not appear that the rate of sanitary dressing noncompliances can be used as a means to 

identify beef trim establishments with a higher probability of having an E. coli O157:H7 positive. In its 

response to OIG, FSIS proposed to revise the sanitary dressing verification Directive 6410.1 with an aim to 

improve and clarify verification of sanitary dressing by FSIS inspectors. This may improve the correlation 

between sanitary dressing noncompliances and E. coli positives in beef trim. 

30 
 

 

 

 

 

11.0 INCREASE SAMPLING DURING THE SUMMER MONTHS
 

E. coli O157:57 concentrations in ground beef and also human illnesses demonstrate seasonality, with higher 

levels occurring during summer months. Thus, one option for increasing the probability of detecting an E. 

coli O157:H7 during MT50 sampling is to increase the number of tests performed during the summer 

months. 

11.1 Seasonality of E. coli O157:H7 Positives 

Table 11-1 presents the number of E. coli positives as a function of month. 81% of E. coli positives in beef 

trim, 53% of E. coli positives in raw ground beef, and 63% of E. coli positives in beef trim suppliers occur in 

the 6 month period May through October. Due to the low number of positives, no seasonality is apparent in 

the number of E. coli positives in bench trim and ground beef components other than trim. 

Table 11- 1 E. coli O157:H7 Positives by Month 2007-June 2011 

2007-June 

2011 Totals 

Raw Ground 

Beef E. coli 

Positives 

Beef Trim 

E. coli 

Positives 

Beef Trim 

Supplier E. coli 

Positives 

Bench Trim 

E. coli 

Positives 

Other 

Components 

E. coli 

Positives 

January 55 1 2 1 0 

February 5 0 3 0 0 

March 6 0 0 0 1 

April 7 2 0 0 0 

May 15 4 0 0 0 

June 24 5 4 0 0 

July 12 3 2 0 0 

August 10 3 2 0 0 

September 20 4 1 1 0 

October 20 6 3 0 0 

November 9 1 1 0 0 

December 6 2 1 0 1 

Table 11-2 presents E. coli O157:H7 percent positive in raw ground beef, beef trim, and beef trim 

suppliers as a function of season. The probability of a beef trim establishment having an E. coli 

O157:H7 positive in May-Oct is 3.8 times higher (two sided Exact Fisher p < 0.002) than in the rest of 

the year. The probability of a beef trim supplier having an E. coli O157:H7 in May-Oct is 1.9 times 

higher (but not statistically significantly so; two sided Exact Fisher p = 0.175) than in the rest of the 

year. There is no statistical difference between the May-Oct E. coli percent positive and the rest of the 

season in bench trim and other ground beef component establishments. The inability to detect a seasonal 

increase in E. coli positives in bench trim suppliers, bench trim and other ground beef component 

establishments is probably due to the small number of E. coli positives in these establishments. 

Table 11- 2 E. coli O157:H7 Percent Positive Seasonality May-Oct 2007-June 2011 

2007-June 2011 May - Oct Rest of Year 

Raw Ground Beef 0.41% 0.14% 

Beef Trim 0.92% 0.25% 

Beef Trim Supplier 0.96% 0.50% 

Bench Trim 0.21% 0.18% 

Other Components 0.00% 0.62% 

31 
 

 

 

 

 

Conclusion: Increasing MT50 sampling during the summer months May-Oct will increase the probability of 

detecting E. coli O157:H7 positives in beef trim. 

11.2 Seasonality of 03J01 and 03J02 Health-Related Noncompliances 

Table 11-3 presents beef trim establishment 03J01 and 03J02 health-related noncompliances as a function of 

seasonality. Contrary to expectations, 03J01 and 03J02 health-related noncompliance rates are not higher 

during the summer months May-Oct. For beef trim establishments, the 03J01 health-related noncompliance 

rate is statistically significantly lower (two sided Exact Fisher p = 0.0017) in the summer months May-Oct 

than in the rest of the year, and there is no statistical difference (two sided Exact Fisher p = 0. 477) between 

seasons in the 03J02 noncompliance rate. 

Table 11- 3 Beef Trim Establishment 03J01 and 03J02 Health-Related Noncompliance Rates 

03J01 03J02 

2007-2011 Noncompliant Compliant Rate Noncompliant Compliant Rate 

May-October 344 74,901 0.46% 363 76,152 0.47% 

Rest of the Months 395 68,072 0.58% 354 70,321 0.50% 

Table 11-4 presents beef trim supplier 03J01 and 03J02 health-related noncompliances as a function of 

seasonality. Again, contrary to expectations, 03J01 and 03J02 health-related noncompliance rates are not 

higher during the summer months May-Oct. In fact, both the 03J01 and 03J02 health-related noncompliance 

rates are statistically significantly lower (two sided Exact Fisher p < 0.0003 and p < 0.03, respectively) in the 

summer months May-Oct than in the rest of the year. 

Table 11- 4 Supplier Establishment 03J01 and 03J02 Health-Related Noncompliance Rates 

03J01 03J02 

2007-2011 Noncompliant Compliant Rate Noncompliant Compliant Rate 

May-October 234 22,349 1.04% 220 21,228 1.07% 

Rest of the Months 302 20,902 1.42% 255 20,054 1.26% 

Conclusion: 03J01 and 03J02 health-related noncompliance rates are not higher during the summer months 

May-Oct in either beef trim establishments or beef trim suppliers. 

32 
 

 

 

 

 

 

 

12.0 INCREASE THE COLLECTION RESPONSE RATE
 

The MT50 beef trim sampling program is intended to include all active, federally inspected beef and 

veal slaughter establishments that produce trim for use in raw ground beef and identified sister 

establishments. There are about 480 slaughter establishments in the MT50 sampling frame at any given 

time, of which about 390 are sampled per year. FSIS selects between 200 and 250 establishments from 

the frame every month, depending upon the number of weeks in a month. Annually, this amounts to 

sending 2600 sample forms per year. However, in CY2010 only 1274 samples were successfully 

collected at beef trim establishments. This is a response rate of about 49%. There are several reasons 

that sample forms mailed out may not result in successful sample collection, including that a sample is 

taken but discarded for various reasons (e.g., sample delivered to laboratory late, laboratory closed, 

container leaking, etc.), that due to conflicts the inspector could not collect a sample, or that the 

establishment was not producing trim during the sampling period. 

The purpose of this section is to determine the probability of E. coli O157:H7 detection if FSIS could 

increase the response rate to 60 or 70 percent. 

Table 12-1 presents the number of samples in each volume class if the collection response rate is 

increased from the current 50 percent to 60% or 70%. For a collection response rate of 60%, the 

expected number of E. coli positives is increased by a factor of 1.2 = 9.0/7.3. For a collection response 

rate of 60%, the expected number of E. coli positives is increased by a factor of 1.4 = 10.5/7.3. 

Table 12- 1 Expected Number of E. coli Positives if Collection Response Rate Increased to 60 or 70 

Percent 

(A) Volume Class (B) 

Number of 

Samples in 2010 

Random Sampling 

Program 

(C) 

Number of Samples in 

2010 Random 

Sampling if Response 

Rate is Increased to 

60% 

(D) 

Number of Samples in 

2010 Random 

Sampling if Response 

Rate is Increased to 

70% 

Very Small 915 1114 1300 

Small 136 176 206 

Medium 93 100 117 

Large 130 169 197 

Total 1,274 1559 1821 

Expected Number of 

E. coli Positives 7.3 9.0 10.5 

Table 12-2 presents the number of samples in each volume class and the expected number of E. coli 

positives if the collection response rate is increased from the current 50 percent to 60% or 70% for a 

sampling design where sampling is proportional to percent positive in the volume class and each 

establishment is sampled at least once. For a collection response rate of 60%, the expected number of E. 

coli positives is increased by a factor of 2.2 = 15.6/7.3. For a collection response rate of 70%, the 

expected number of E. coli positives is increased by a factor of 2.5 = 18.5/7.3. 

33 
Table 12- 2 Expected Number of Beef Trim E. coli Positives under Sampling Proportional to E. 

coli Percent Positive with at Least One Sample per Establishment and Increased Collection 

Response Rates 

(A) 

Volume 

Class 

(B) 

Number of 

Samples in 

2010 

Random 

Sampling 

Program 

(C) 

Number of Samples 

Based on Sampling 

Proportional to E. 

coli Percent Positive 

& at Least 1 Sample 

per Plant 

(D) 

Number of Samples 

Based on Sampling 

Proportional to E. 

coli Percent Positive 

& at Least 1 Sample 

per Plant & 60% 

Response Rate 

(E) 

Number of Samples 

Based on Sampling 

Proportional to E. coli 

Percent Positive & at 

Least 1 Sample per 

Plant & 70% 

Response Rate 

Very Small 915 292 357 417 

Small 136 488 597 697 

Medium 93 368 451 526 

Large 130 126 154 180 

Total 1,274 1,274 1559 1821 

Expected 

Number of 

E. coli 

Positives 7.3 12.96 15.58 18.52 

Conclusion: These results demonstrate that increasing E. coli O157:H7 collection response rate 

provides an effective means of increasing the probability of detecting an E. coli positive in beef trim 

establishments. 

An additional means of increasing the number of samples successfully obtained is to increase the 

number of sample forms mailed each year, called over-scheduling to adjust for non-response. Increasing 

the number of sample forms sent out by 20% will increase the number of successful samples collected 

by 20%, even if the collection response rate remains at 49%. This would result in an effective collection 

rate of 70% and would not increase the workload of the laboratories above its currently acceptable load 

of 2600 analyzed samples per year. 

34 
 

 

 

 

 

13.0 MISCELLANEOUS
 

The purpose of this section is to evaluate two miscellaneous issues. 

13.1 Geographical Distribution of Beef Trim E. coli O157:H7 Positives 

Table 13-1presents the E. coli O157:H7 test results by FSIS district for beef trim establishments tested 

under the beef trim sampling program MT50 during the years 2008-June 2011. The E. coli percent 

positives in district 5 and district 35 are not statistically significantly different (two sided Exact Fisher p 

= 0.675). The E. coli percent positive in district 5 is statistically significantly higher than the remaining 

districts except for districts 40, 45, 25, and 30. 

Table 13- 1 Geographical Distribution of Beef Trim E. coli O157:H7 Positives 

District 

Number 

District 

Name 

Number 

Establishments 

in District 

Positives Total 

Tests Rate 

5 Alameda 19 5 203 2.46% 

35 Springdale 11 1 84 1.19% 

90 Ridgeland 17 1 105 0.95% 

80 Raleigh 27 2 216 0.93% 

20 Minneapolis 43 4 436 0.92% 

50 Lombard 22 2 275 0.73% 

65 Albany 46 3 426 0.70% 

85 Atlanta 21 1 145 0.69% 

60 Philadelphia 49 3 559 0.54% 

15 Denver 79 4 887 0.45% 

75 Beltsville 31 1 249 0.40% 

40 Dallas 31 1 364 0.27% 

45 Madison 35 1 380 0.26% 

25 Des Moines 30 1 411 0.24% 

30 Lawrence 48 1 413 0.24% 

13.2 Beef Trim Versus Veal 

The purpose of this section is to determine if there is a difference in the E. coli O157:H7 percent positive 

for trim and ground beef produced from younger cattle (veal) versus older cattle. 

Table 13-2 presents the E. coli percent positive for ground beef versus ground veal. The probability of 

detecting an E. coli O157:H7 percent positive in ground veal is 19.2 times higher than in ground beef. 

This difference is statistically significant (Two-Sided Fisher Exact p = 0.008). This conclusion is based 

on limited samples in raw ground veal. If this conclusion is confirmed as more samples accumulate, it is 

proposed that sampling rates in establishments producing ground veal be increased. 

35 
 

 

 

 

 

 

Table 13- 2 E. coli O157:H7 Percent Positive in Ground Beef and Ground Veal 

E. coli Number Percent 

Positives Samples Positive 

Ground Beef 6 9605 0.06% 

Ground Veal 2 174 1.15% 

Table 13-3 presents the E. coli percent positive for beef trim and veal trim. The difference is not 

statistically significantly different (Two-Sided Fisher Exact p = 0.168). 

Table 13- 3 E. coli O157:H7 Percent Positive in Beef Trim and Veal Trim 

E. coli Number Percent 

Positives Samples Positive 

Beef Trim 4 986 0.41% 

Veal Trim 1 36 2.78% 

It is proposed that the issue of whether the E. coli O157:H7 percent positive rate in veal trim 

establishments is higher than that of beef trim establishments be reevaluated after additional data is 

gathered in veal trim establishments. 

36 
 

 

 

 

 

 

 

 

14.0 DISCUSSION AND RECOMMENDATIONS
 

This report reviews eight options for redesign of the FSIS E. coli O157:H7 beef trim, bench trim, and 

other ground beef component sampling programs. The major observations are 

Over the period 2007-June 2011, beef trim sampling produced 31 E. coli O157:H7 positives 

(0.60% positive rate), bench trim sampling produced 2 positives (0.19% positive), and raw 

ground beef components other than trim sampling produced 2 positives (0.28% positive). Within 

each of these three sampling programs, there is no statistically significant difference in the E. 

coli O157:H7 percent positives between years. 

The probability of detecting an E. coli O157:H7 positive in beef trim is 2.2 times higher than in 

raw ground beef (two sided Exact Fisher, p < 0.0002). The E. coli percent positives in bench trim 

and raw ground beef components other than trim are statistically significantly lower than that of 

beef trim and are not statistically significantly different than that found in raw ground beef. 

The probability of detecting an E. coli O157:H7 positive during follow-up sampling after an E. 

coli O157:H7 positive in a beef trim establishment are 6.6 times higher than under routine beef 

trim E. coli sampling (two sided Exact Fisher p < 0.00001). No positives were detected during E. 

coli O157:H7 follow-up sampling for bench trim or other ground beef components after an E. 

coli positive. 

Sampling beef trim establishments proportional to production volume and requiring that each 

establishment is sampled at least once per year is 1.01 times more likely to detect an E. coli 

O157:H7 positive than the 2010 MT50 random sampling program. 

Establishments that supply beef trim to raw ground beef establishments that test positive for E. 

coli O157:H7 are termed beef trim suppliers. If it is the only supplier to the ground beef 

establishment, it is termed a sole beef trim supplier. These establishments are tested under the 

MT52 program. The E. coli percent positives in beef trim suppliers (0.73%) and sole beef trim 

suppliers (0.69%) are not statistically different than that found in the MT50 beef trim sampling 

program (0.60%). The E. coli percent positives in other ground beef component suppliers 

(0.62%) and sole ground beef component suppliers (0.61%), while higher, are not statistically 

different than that found in the MT54 sampling of other ground beef components (0.28%). 

No association was found between health-related regulatory noncompliances and the probability 

of E. coli O157:H7 positive sample results. 

No association was found between higher sanitary dressing noncompliances and the probability 

of E. coli O157:H7 positive sample results. 

37 
 

 

 

 

 

 

 

 

 

 

 

There is a definite seasonality in E. coli O157:H7 rate in beef trim and beef trim suppliers. The 

probability of detecting an E. coli O157:H7 positive in a beef trim establishment during May-Oct 

is 3.8 times higher than in the rest of the year (two sided Exact Fisher p < 0.002). The probability 

of a beef trim supplier having an E. coli O157:H7 in May-Oct is 1.9 times higher (but not 

statistically significantly so, two sided Exact Fisher p = 0.175) than in the rest of the year. Due to 

the low number of positives, no seasonality is apparent in the number of E. coli positives in 

bench trim and ground beef components other than trim. 

The probability of detecting an E. coli O157:H7 positive in raw ground veal is 19.2 times higher 

than in raw ground beef and the difference is statistically significant. 

Of the options reviewed, the ones that appear most promising for increasing the probability of detecting E. 

coli O157:H7 positives during FSIS verification testing are to increase E. coli O157:H7 sampling in 

The volume class with the highest E. coli O157:H7 percent positive.
 

The volume class with the highest volume-weighted percent positives.
 

The six month warm weather period when E. coli O157:H7 positives are the highest. 

Conclusion: 

Either of the following two designs for testing beef trim, bench trim, and raw ground beef components 

other than trim increases the probability of detecting E. coli O157:H7 positives during FSIS verification 

testing. 

Sampling volume classes in proportion to the E. coli O157:H7 percent positive, insuring that 

each establishment is sampled at least once per year, and increasing samples during summer 

months by 20% increases the probability of detecting an E. coli positive by a factor of 2.0. 

Sampling proportional to volume-weighted percent positive, insuring that each establishment is 

sampled at least once per year, and increasing samples during summer months by 20% increases the 

probability of detecting an E. coli positive by a factor of 1.4. 

Of the two sampling designs, sampling volume classes in proportion to the E. coli O157:H7 percent 

positive provides the largest increase in the probability of identifying establishments that may not be 

effectively controlling E. coli O157:H7. 

FSIS will redesign E. coli verification testing in establishments producing beef manufacturing trimmings 

so that sampling is weighted by production volume and volume class-specific risk factor, ensures that 

each establishment is sampled at least once per year, and increases samples during summer months by 

20%. This will increase the probability of detecting E. coli O157:H7 positives during FSIS verification 

testing in beef trim establishments by about a factor of 2 and increase the degree of confidence of 

identifying establishments that may not be effectively controlling E. coli O157:H7. FSIS will also increase 

the number of samples successfully collected (through a combination of allocating more resources in 

establishments more likely to collect and overscheduling to adjust for non-response) with the goal eventually 

of collecting 100% of the budgeted agency resources. This will increase the overall probability of detecting 

beef trim E. coli O157:H7 positives during FSIS verification testing by a factor of about 2.5. Additionally, 

38 
 

 

FSIS is considering revising the sampling programs for bench trim and other ground beef components 

similar to that discussed for beef manufacturing trimmings. 

FSIS will continue to conduct follow up E. coli sampling in establishments with an E. coli O157:H7 

positive in beef trim, bench trim, other components, and in supplier establishments. Under these 

programs, sixteen follow-up samples are scheduled at establishments with an E. coli positive unless the 

establishment is a low volume producer (less than 1,000 lbs. per day), where eight follow-up samples 

are scheduled. These follow up programs provide for repeated testing over a relatively short time period 

and increase confidence in the Agency’s judgment as to whether tested establishments are effectively 

controlling E. coli O157:H7. 

The conclusions of this report may need to be reassessed for non-O157 Shiga toxin-producing serotypes 

of Escherichia coli (STEC) once FSIS STEC testing has been in place for at least a year. FSIS will likely 

start STEC testing in June 2012. 

39 
 

 

 

 

 

15.0 STATISTICAL SAMPLING DESIGN
 

FSIS assessed over 30 discrete sampling designs and their related probabilities to detect E. coli O157:H7 

in beef manufacturing trimmings. The design the agency chose to implement is weighted, random 

sampling with replacement that accounts for both the production volume and percent positive of volume 

classes. The agency also chose to over-schedule seasonally during the high prevalence season, overschedule to adjust for non-response, implement an annual scheduling floor, and implement monthly 

scheduling ceilings. The chosen design gives FSIS an increased likelihood of 2.46 to detect E. coli 

O157:H7 as compared to the current design of simple random sampling without replacement. 

FSIS plans to implement this new sampling design starting in April 2012, with some aspects, like 

scheduling floors, seasonal adjustment, and over-scheduling, being phased in gradually. Additionally, 

FSIS plans to re-evaluate risk factors using FSIS and available published, scientific data every few years 

to ensure the riskiest groups are being targeted correctly. 

15.1 Sampling Frame 

The sampling frame is the list of all establishments eligible for the sampling program. This includes all 

establishments whose Public Health Information System (PHIS) establishment profiles indicate they 

make beef manufacturing trimmings. 

15.2 Sample Size 

This is the number of sampling requests scheduled on a monthly basis. The sample size is 217 requests 

per month, which is 2604 requests per year. FSIS intends to begin adjusting the number per month for 

seasonality of prevalence. Under seasonality, 60% of the annual sampling resources would be allocated 

in high prevalence season (May – October) and 40% would be allocated in low prevalence season. FSIS 

also intends to begin gradually over-scheduling to adjust for non-response so that FSIS collects and 

analyzes 2600 samples in a 12-month period. 

15.3 Annual Sampling Floor 

This is the minimum number of analyses FSIS will allow at each establishment in the sampling frame in 

a 12-month period. The proposed annual sampling floor is one. FSIS intends to gradually implement 

this sampling floor starting with the largest producers. This floor is listed in table 15-1. 

15.4 Monthly Sampling Ceiling 

This is the maximum number of requests a given establishment could receive in any one month. FSIS 

intends to impose monthly sampling ceilings by production volume group. These ceilings are listed in 

table 15-1. 

40 
Table 15- 1 Monthly Sampling Ceilings and Annual Sampling Floor by Production Volume Group 

PHIS Volume Group 

Estimated Production 

Volume 

Monthly Sampling 

Ceiling Annual Sampling Floor 

Group 1 < 1001 lbs/day 1 1 

Group 2 1001 – 3000 lbs/day 2 1 

Group 3 3001 – 6000 lbs/day 2 1 

Group 4 6001 – 50,000 lbs/day 2 1 

Group 5 50,001 – 250,000 lbs/day 3 1 

Group 6 250,001 – 600,000 lbs/day 4 1 

Group 7 >600,000 lbs/day 4 1 

Group 99 Unknown 1 1 

PBIS 

Volume Groups 

PHIS 

Volume Groups 

Multi-Year 

Percent 

Positive 

Risk 

Factor 

(A) 

Daily 

Volume 

Estimate 

Volume 

Score 

(B) 

Sampling 

Weight 

(A * B) 

Very Small 

< 1001 lbs/day 

Group 1 

< 1001 lbs/day 0.42% 0.7 500 1 0.7 

Small 

1001 – 50,000 lbs/day 

Group 2 

1001 – 3000 lbs/day 

1.47%* 2.45 

2000 4 9.8 

Group 3 

3001 – 6000 lbs/day 4500 9 22.05

Group 4 

6001 – 50,000 lbs/day 28,000 56 137.2 

Medium 

50,001 – 250,000 lbs/day 

Group 5 

50,001 – 250,000 lbs/day 1.11% 1.85 150,000 300 555 

Large 

>250,000 lbs/day 

Group 6 

250,001 – 600,000 lbs/day 0.38% 0.63 

425,000 850 535.5 

Group 7 

>600,000 lbs/day 

800,000 

(assumed) 1600 1008 

Unknown volume 

Group 99 

Unknown volume NA 1 NA 1600 1600

Total 0.60% 

 

15.5 Sampling Weights 

The sampling weights are the product of the volume score and the risk factor. Based upon the research 

presented in the previous chapters of this paper, FSIS chose to implement the risk factors shown in 

Table 15-2. FSIS may choose to incorporate more risk factors or to adjust those chosen below based 

upon new scientific data available to the Agency or from regular re-assessment of FSIS’s own data. 

Table 15- 2 Calculation of Sampling Weights by Production Volume Group 

* The small group’s percent positive is statistically significantly higher than in the large and very small. 

The multi-year (overall) percent positive is that reported in chapter 6 of this paper. The risk factor is 

calculated as follows: 

Percent positive

risk factor ൌ in a given volume group i. e. very small risk factor ൌ 0.42%

Overal percent positive , 0.60% ൌ 0.7 

41 

	

The daily volume estimate is the midpoint of the volume range. The volume score is the normalized 

daily volume estimate, so that the volume score = daily volume estimate / the smallest daily volume 

estimate. 

The sampling weight is the product of the risk factor and the volume score. 

So, using the medium group as an example and the values from table 15-2, above, the sampling weight 

is calculated as follows: 

Medium lume 

0.60% ൈ 

150,000

sampling weight ൌ 

risk

score 

ൌ 

0.42% ൌ 1.85 ൈ 300 ൌ 555 factor ൈ vo

500 

15.5.1 Scaling Factors on Volume Scores 

At this time, FSIS does not intend to apply scaling factors to the volume score. However, it may decide 

to do so in the future. The following formula would be used to scale down the volume scores to a 

ܸ௜ ሺ

൅ ௅ ܵ ൌ௜ ݏݒ

chosen interval. 

ሻ ܵு െ ܵ௅ ሻሺ െ ܸଵ

 ܸ଻ െ ܸଵ

 = Daily volume production for establishment in category i ܸ௜

ܸ଻ = Maximum daily production volume 

 ܸଵ = Minimum daily production volume 

SH = High scaling factor 

SL = Low scaling factor
 

15.5.2 Calculating Probability of Selection 

The probability of selection for establishment j is its weight divided by the sum of all n weights. The 

following formula is used, where vs is the volume score and rf is the risk factor. 

∑ ൌ௝ ݌

ݏݒ ௝ ݎ · ݂ ௝

 ୀଵ ௝ݏݒ ௝ ݎ · ݂ ௝

௡

15.6 Historical Collection Rates 

Historically, one of the leading causes of FSIS’s low response rate was due to the sampling design. 

These rates are consistent year to year as well as across seasons. Increasing the number of scheduled 

samples can be used to adjust for the low response rates. Historical collection rates are given in Table 

15-3. 

42 
 

 

 

 

 

Table 15- 3 Historical Collection Rates by Production Volume Group 

PHIS Volume 

Group 

Estimated Production 

Volume 

Collection 

Rate1 

Establishment 

Count2 

Group 1 < 1001 lbs/day 58% 278 

Group 2 1001 – 3000 lbs/day 76% 36 

Group 3 3001 – 6000 lbs/day 75% 19 

Group 4 6001 – 50,000 lbs/day 75% 30 

Group 5 50,001 – 250,000 lbs/day 82% 19 

Group 6 250,001 – 600,000 lbs/day 89% 19 

Group 7 >600,000 lbs/day 82% 19 

Group 99 Unknown volume 55% 4 

15.7 Theoretical Sampling Distribution 

Below is a theoretical distribution of FSIS sampling resources for this sampling design. It also presents 

an estimate of the number of analyses FSIS could expect to perform annually based upon the design and 

historical collection rates. This distribution reflects all aspects of the design—some of these aspects will 

be phased in gradually by the Agency. 

Table 15- 4 Theoretical Monthly and Annual Sampling Distribution with Estimated Annual 

Collection 

Increased ability to detect E. coli 

O157:H7 = 2.46 

Volume Group Grand 

Total Unknown Large Medium Small Very Small 

99 7 6 5 4 3 2 1 

Number of establishments 4 19 19 19 30 19 37 277 424 

Monthly sampling ceiling 1 4 4 3 2 2 2 1 NA 

Historical Collection Rate 55% 82% 89% 82% 75% 75% 76% 58% 

Number of Samples Requested 

(HIGH prevalence season month) 4 76 76 57 60 24 19 9 325 

Number of requests per establishment 

(HIGH prevalence season month) 1 4 4 3 2 1.26 0.51 0.03 

Estimated Analyses per month 

(HIGH prevalence season month) 2 62 68 47 45 18 14 5 261 

Number of Samples Requested 

(LOW prevalence season month) 4 71 51 53 28 6 1 1 215 

Number of requests per establishment 

(LOW prevalence season month) 1 3.74 2.68 2.79 0.93 0.32 0.03 0.00 

Estimated Analyses 

(LOW prevalence season month) 2 58 45 43 21 5 1 1 176 

Number of samples requested per 

establishment (YEAR) 12 46.42 40.11 34.74 17.6 9.47 3.24 0.22 

Estimated Analyses 26 723 678 541 396 135 91 35 2622 

15.8 Increased ability to detect E. coli O157:H7 

This new design was compared to the current design to calculate the ability of the new design to detect 

E. coli O157:H7 as compared to the current design. The new design has an increased ability of 2.46 to 

1 Results based on 2007 – 2011 collection rates. Collection rates were consistent over the analysis years. 2 Sampling frame distribution extracted from the FSIS PHIS database on February 7, 2012. 

43 
Annual High Season Low Season 

PHIS 

Volume 

Group 

Current 

Design 

Estimated 

Analyses 

2007 – 

2011 

Percent 

Positive 

Current 

Design 

Expected 

Positives 

2007-

2011 

Percent 

Positive 

New 

Design 

Estimated 

Analyses 

New 

Design 

Expected 

Positives 

2007-

2011 

Percent 

Positive 

New 

Design 

Estimated 

Analyses 

New 

Design 

Expected 

Positives 

99 26 2.17% 0.57 4.76% 12 0.57 0.00% 12 0.00

7 108 0.00% 0.00 0.00% 372 0.00 0.00% 348 0.00

6 75 0.30% 0.23 0.52% 408 2.12 0.00% 270 0.00

5 69 1.99% 1.37 2.96% 282 8.35 0.75% 258 1.94

4 126 0.39% 0.49 0.75% 270 2.03 0.00% 126 0.00

3 90 3.10% 2.79 4.76% 108 5.14 1.52% 30 0.46

2 155 1.40% 2.17 1.27% 84 1.07 1.56% 6 0.09

1 1023 0.12% 1.24 0.11% 30 0.03 0.13% 6 0.01

TOTAL 1,672 8.85 1,566 19.31 1,056 2.49

ൌ ൌ ൌ 2.46 

 

detect O157:H7. No predictions can be made for non-O157 STEC because FSIS has not yet begun 

testing for these pathogens, and the previous design will never have been implemented with additional 

STEC testing. 

Table 15- 5 Computation of Increased Ability Compared to Previous Current Design 

Table 

New Design High Season

 ൅ New Design Low Season 

Ability to Detect Expected Positives Expected Positives 19.31 ൅ 2.49

ܧ. ܿ݋݈݅ Positives Previous Design 8.85

Expected Positives 

15.9 Prevalence estimation 

The current agency resources may not support prevalence estimation. If the annual sample size were 

increased, then this design could be used to calculate prevalence in beef manufacturing trimmings. 

44 
 

 

 

 

16.0 REFERENCES 

1.	 Office of Inspector General (OIG) 2011, FSIS Sampling Protocol for Testing Beef Trim for 

E. coli O157:H7 

2.	 Food Safety and Inspection Service (FSIS) 2011, Food Safety and Inspection Service Sampling 

Protocol for Testing Beef Trim for E. coli O157:H7 – Phase I 

3.	 Food Safety and Inspection Service (FSIS) December 2011, Report on the Food Safety and 

Inspection Service’s Microbiological and Residue Sampling Programs

4.	 Food Safety and Inspection Service (FSIS) November 3, 2011, FSIS Directive 6410.1, Rev. 1: 

Verifying sanitary dressing and process control procedures by off-line inspection program 

personnel (IPP) in slaughter operations of cattle of any age 

5.	 Food Safety and Inspection Service (FSIS) March 31, 2010, FSIS Directive 10,010.1, Rev. 3: 

Verification activities for Escherichia coli O157:H7 in raw beef products 

6.	 Food Safety and Inspection Service (FSIS) June 24, 2011, FSIS Directive 5000.1, Rev. 3: 

Verifying an establishment’s food safety system 

7.	 Food Safety and Inspection Service (FSIS) 2001, Risk Assessment of the Public Health Impact 

of Escherichia coli O157:H7 in Ground Beef 

8.	 International Commission on Microbiological Specifications for Foods (ICMSF) 

http://www.icmsf.org/ 

45 
 

 

 

 

17.0 APPENDECIES
 

Appendix A - N60 Sample Collection Method 

FSIS uses a sample collection method called N60 to test for E. coli O157:H7 in beef trim. Under the 

N60 collection method, the inspector collects 60 pieces of beef trim from a production lot of beef cuts or 

trimmings that will be used for the making of ground beef. Each of the 60 pieces is a slice cut off of the 

surface of trimmings that is approximately 3 inches long by 1 inch wide and 1/8 inch thick. The priority 

is to collect samples from pieces of product taken from the original external surface of the beef carcass 

(this is the outside surface of the carcass after the hide is removed). Sixty pieces that are 3 inches long 

by 1 inch wide and 1/8 inch thick should weigh approximately 3⁄4 lb. The sixty pieces are placed in a 

bag. An additional 1 1/4 pounds (approximately) of available smaller pieces of beef manufacturing 

trimmings from the same specific production lot are selected and placed in a second bag. The total 

weight of the 2 bags of samples is approximately 2 pounds. The N60 method is resource intensive, often 

taking inspection program personnel over an hour to collect a sample. The sample is shipped to a 

designated FSIS laboratory where it is composited for testing to determine the presence of E. coli 

O157:H7. The N60 method of sample collection is recommended by the International Commission on 

Microbiological Specifications for Foods (ICMSF). 

46 
 

 

 

 

 

 

 

 

 

Appendix B - Volume-Weighted E. coli Percent Positive in Beef Trim 

FSIS inspectors record a daily volume estimate when taking a beef trim sample. The volume weights are 

recorded as one of four daily production volume groups which translate into the annual beef trim 

volumes given in Table B-1. 

Table B- 1 Volume Groups for Beef Trim Sampling 

Volume Group Daily trim volume 

in lbs/day 

Assumed 

Production 

Days 

Estimated annual trim 

volume in lbs/yr 

Very Small < 1,000 250 75,000 

Small 1,000 – 50,000 250 6,375,000 

Medium 50,001 – 250,000 250 37,500,000 

Large > 250,000 150 93,750,000 

Table B-2 presents the estimated annual beef trim volume for beef trim establishments tested for E. coli 

O157:H7 in each of the years. Since not all beef trim establishments are tested every year, the actual 

annual volume of beef trim produced in the U.S. should be slightly larger than these estimates. The 

establishments tested under the MT50 beef trim sampling program produce about 4 billion pounds of 

beef trim annually. 

Table B- 2 Beef Trim Volume of Establishments Tested for E. coli O157:H7 

Year 

Number Establishments 

Tested 

Annual Beef Trim Volume in 

Billion Pounds/yr 

2007 336 4.3 

2008 344 3.9 

2009 368 3.8 

2010 386 3.9 

Table B-3 presents the E. coli test results as a function of beef trim volume produced for the years 

CY2007 through June 2011 combined. The data were combined since no statistically significant 

difference was found in the E. coli O157:H7 positive rates in the years CY2007 through June 2011. In 

addition, combining the data produces a larger number of samples from each trim volume class and thus 

produces more accurate estimates of the percent positive for each volume class. The large volume class 

has the smallest E. coli percent positive, while the small volume class has the highest E. coli percent 

positive and these rates are marginally statistically different (one-sided Fisher exact p = 0.053). 

However, there is no statistically significant difference in the E. coli O157:H7 percent positives for the 

medium and large beef trim volume classes. The E. coli O157 percent positives for very small 

establishments are statistically significantly less than that of the small and medium beef trim volume 

classes. 

Sampling in the small volume class has a 3.9 times greater odds of detecting an E. coli O157:H7 positive 

than sampling in the large volume class (confidence interval 0.84 to 18.1). 

47 
 

 

 

 

 

 

 

 

 

 

Table B- 3 E. coli O157:H7 Percent Positive for Beef Trim as a Function of Beef Trim Volume 

Produced for the Years CY2007 - June 2011 

CY07-CY11 Beef Manufacturing Trim 

Beef Trim 

# of unique 

plants 

Number 

Positives 

Number Total 

Tests % Positive 

Very Small 408 15 3,558 0.42% 

Small 93 9 612 1.47% 

Medium 41 5 452 1.11% 

Large 40 2 530 0.38% 

Total 582 31 5,152 0.60% 

Weighting the individual E. coli O157:H7 percent positives in Table B-3 by the corresponding fraction 

of total beef trim volume in each volume class provides an alternative estimate of the “average” E. coli 

O157:H7 percent positive in beef trim. Such an estimate is called a volume-weighted percent positive. 

Table C-4 presents an estimate of the volume-weighted percent positive for E. coli O157:H7 in beef trim 

based on cumulative data for the years CY2007 through June 2011. The volume-weighted percent 

positive over these years is 0.63%. 

As an example of computing the weighted percent positives entries in the last column of Table B-4, 

consider the 0.27% in the medium volume class. This number is computed as 

0.27% = 1.11% (from table B-3) *(volume of the medium volume class/total volume of all volume 

classes) = 1.11% *(4,762,500,000/19,545,000,000) = 0.27%. The 0.63% is the sum of the weighted 

percent positives for all volume classes. 

Table B- 4 E. coli O157:H7 Beef Trim Volume Weighted Percent Positive for Years CY2007 -

June 2011 

Trim 

Volume 

Class 

# of 

unique 

plants 

Trim volume 

CY2007-June 

2011 (pounds) 

% of Total 

Volume 

Number 

Samples 

% of Total 

Samples 

Unweighted 

% Positive 

Weighted 

% Positive 

Very 

Small 

408 

95,025,000 0.49% 3,558 69.06% 0.42% 0.00% 

Small 93 1,268,625,000 6.48% 612 11.88% 1.47% 0.10% 

Medium 41 4,725,000,000 24.12% 452 8.77% 1.11% 0.27% 

Large 40 13,500,000,000 68.92% 530 10.29% 0.38% 0.26% 

Total 582 18,588,650,000 100.00% 5,152 100.00% 0.60% 0.63% 

Table B-5 summarizes estimates of the E. coli O157:H7 volume-weighted percent positive for beef trim 

by year. 

48 
Table B- 5 E. coli O157:H7 Volume Weighted Percent Positives for Beef Trim by Year 

Year 

Un-weighted 

Percent Positive 

Volume-Weighted 

Percent Positive 

2007 0.28% 0.67% 

2008 0.90% 0.80% 

2009 0.73% 0.28% 

2010 0.31% 0.15% 

Jan-June 2011 0.67% 1.52% 

2007-June 2011 0.60% 0.62% 

49 
 

 

 

 

 

 

 

Appendix C - Probability of Detection of Beef Trim E. coli O157:H7 Positives 

The purpose of this appendix is to demonstrate how the probability of detecting an E. coli O157:H7 

positive is calculated under various beef trim sampling approaches. 

C-1 Probability of Detection of E. coli O157:H7 Positives under Sampling Proportional to Volume 

Table C-1 presents the expected number of E. coli O157:H7 positives resulting from sampling programs 

based on (1) the current (2010) sampling program which selects beef trim establishments at random and 

(2) a sampling program where the number of samples in each volume class is proportional to the volume 

of the volume class. As expected under a random sampling program, the fraction of samples in each 

volume class for the 2010 random sampling program (column D) is approximately equal to the fraction 

of beef trim establishments in each volume class. The expected number of samples under the 2010 

random sampling program (column G) is computed as the product of the number of samples in each 

volume class for the 2010 sampling program (column D) times the average E. coli percent positive in 

each volume class (column F). The expected number of samples under a sampling program based on the 

percent volume in each volume class (column H) is computed as the product of the number of samples 

in each volume class for the percent volume sampling program (column E) times the average E. coli 

percent positive in each volume class (column F). The odds of detecting an E. coli positive under the 

percent volume sampling program are 1.08 higher than under the current 2010 random sampling 

program. This is computed as the ratio of the expected number of positives under each sampling 

program (1.08 = 7.99/7.37). 

Table C- 1 Expected Number of Beef Trim E. coli Positives under Sampling Proportional to 

Volume 

(A) 

Volume 

Class 

(B) 

Total 

Volume 

CY2007-

June 2011 

(pounds) 

(C) 

Percent 

of Total 

Volume 

(D) 

Number of 

Samples 

Based on 

2010 

Random 

Sampling 

Program 

(E) 

Number of 

Samples Based 

on Sampling 

Proportional 

to Volume in 

Volume Class 

(F) 

Average 

CY2007-

June 

2011 

Percent 

Positive 

(G) 

Expected 

Positives 

Based on 

2010 

Sampling 

Program 

(H) 

Expected 

Positives 

Based on 

Sampling 

Proportional 

to Volume 

Very 

Small 0.09 Billion 0.49% 915 6 0.42% 3.84 0.03 

Small 1.3 Billion 6.48% 136 83 1.47% 2.00 1.21 

Medium 4.8 Billion 24.12% 93 307 1.11% 1.03 3.41 

Large 13.4 Billion 68.92% 130 878 0.38% 0.49 3.34 

Total 19.5 Billion 100.00% 1,274 1,274 0.60% 7.37 7.99 

Table C-2 presents the expected number of beef trim E. coli O157:H7 positives resulting from sampling 

programs based on (1) the current (2010) sampling program which selects beef trim establishments at 

random and (2) a sampling program in which the number of samples in each volume class is 

proportional to the volume of the volume class and each establishment is sampled at least once per year. 

50 
 

 

 

 

 

 

 

 

The odds of detecting an E. coli positive under the percent volume sampling program with at least one 

sample per establishment are 1.01 times higher than under the current 2010 random sampling program. 

This is computed as the ratio of the expected number of positives under each sampling program (1.01 = 

7.42/7.37). 

Table C- 2 Expected Number of Beef Trim E. coli Positives under Percent Volume Sampling 

Program with at Least One Sample per Establishment. 

(A) 

Volume 

Class 

(B) 

Total 

Volume 

CY2007-

June 2011 

(pounds) 

(C) 

Percent 

of Total 

Volume 

(D) 

Number of 

Samples 

Based on 

2010 

Random 

Sampling 

Program 

(E) 

Number of 

Samples 

Based on 

Sampling 

Proportional 

to Volume 

& at Least 1 

Sample per 

Plant 

(F) 

Average 

CY2007-

June 

2011 

Percent 

Positive 

(G) 

Expected 

Positives 

Based on 

2010 

Sampling 

Program 

(H) 

Expected 

Positives 

Based on 

Percent 

Volume 

Sampling 

Program 

Very 

Small 0.09 Billion 0.49% 915 292 0.42% 3.84 1.23 

Small 1.3 Billion 6.48% 136 65 1.47% 2.00 0.95 

Medium 4.8 Billion 24.12% 93 240 1.11% 1.03 2.67 

Large 13.4 Billion 68.92% 130 677 0.38% 0.49 2.57 

Total 19.5 Billion 100.00% 1,274 1,274 0.60% 7.37 7.42 

C-2 Probability of Detection of E. coli O157:H7 Positives under Sampling Proportional to E. coli 

Percent Positive 

Table C-3 presents the expected number of E. coli O157:H7 positives resulting from sampling programs 

based on (1) the current (2010) sampling program which selects beef trim establishments at random and 

(2) a sampling program where the number of samples in each volume class is proportional to the E. coli 

percent positive of the volume class. The expected number of samples under the 2010 random sampling 

program (column F) is computed as the product of the number of samples in each volume class for the 

2010 sampling program (column B) times the average E. coli percent positive in each volume class 

(column D). The expected number of samples under a sampling program based on the E. coli percent 

positive in each volume class (column G) is computed as the product of the number of samples in each 

volume class for the E. coli percent positive sampling program (column C) times the average E. coli 

percent positive in each volume class (column D). The odds of detecting an E. coli positive under the 

sampling program where the number of samples in each volume class is proportional to the E. coli 

percent positive of the volume class are 1.9 times higher than under the current 2010 random sampling 

program. This is computed as the ratio of the expected number of E. coli positives under each sampling 

program (1.9 = 14.00/7.37) 

51 
 

 

 

 

 

 

 

 

 

 

 

 

Table C- 3 Expected Number of Beef Trim E. coli Positives under Sampling Proportional to E. coli 

Percent Positive. 

.(A) 

Volume 

Class 

(B) 

Number of 

Samples 

Based on 

2010 Random 

Sampling 

Program 

(C) 

Number of 

Samples Based 

on Sampling 

Proportional to 

E. coli Percent 

Positive in 

Volume Class 

(D) 

Average 

CY2007-

June 

2011 

Percent 

Positive 

(E) 

Fractional 

Percent 

Positive 

(F) 

Expected 

Positives 

Based on 

2010 

Sampling 

Program 

(G) 

Expected 

Positives Based 

on Sampling 

Proportional to 

E. coil Percent 

Positive in 

Volume Class 

Very 

Small 915 158 0.42% 12.4% 3.84 0.66 

Small 136 554 1.47% 43.5% 2.00 8.14 

Medium 93 418 1.11% 32.8% 1.03 4.64 

Large 130 143 0.38% 11.2% 0.49 0.54 

Total 1,274 1274 0.60% 100.0% 7.37 14.00 

Table C-4 presents the expected number of beef trim E. coli O157:H7 positives resulting from sampling 

programs based on (1) the current (2010) sampling program which selects beef trim establishments at 

random and (2) a sampling program in which the number of samples in each volume class is 

proportional to the percent positive of the volume class and each establishment is sampled at least once 

per year. The odds of detecting an E. coli positive under the percent positive sampling program with at 

least one sample per establishment are 1.8 times higher than under the current 2010 random sampling 

program. This is computed as the ratio of the expected number of positives under each sampling 

program (1.8 = 12.96/7.37). 

Table C- 4 Expected Number of Beef Trim E. coli Positives under Sampling Proportional to E. coli 

Percent Positive with at Least One Sample per Establishment 

(A) 

Volume 

Class 

(B) 

Number of 

Samples 

Based on 

2010 Random 

Sampling 

Program 

(C) 

Number of 

Samples Based 

on Sampling 

Proportional to 

E. coli Percent 

Positive in 

Volume Class 

& at Least 1 

Sample per 

Plant 

(D) 

Average 

CY2007-

June 

2011 

Percent 

Positive 

(E) 

Fractional 

Percent 

Positive 

(F) 

Expected 

Positives 

Based on 

2010 

Sampling 

Program 

(G) 

Expected 

Positives Based 

on Sampling 

Proportional to 

E. coil Percent 

Positive in 

Volume Class 

Very 

Small 915 292 0.42% 12.4% 3.84 1.23 

Small 136 488 1.47% 43.5% 2.00 7.17 

Medium 93 368 1.11% 32.8% 1.03 4.09 

Large 130 126 0.38% 11.2% 0.49 0.48 

Total 1,274 1,274 0.60% 100.0% 7.37 12.96 

52 
 

 

 

 

 

 

 

 

C-3 Probability of Detection of E. coli O157:H7 Positives under Sampling Proportional to Volume 

Weighted Percent Positive 

Table C-5 presents the expected number of E. coli O157:H7 positives resulting from sampling programs 

based on (1) the current (2010) sampling program which selects beef trim establishments at random and 

(2) a sampling program which the number of samples in each volume class is proportional to the volume 

weighted percent positive of the volume class. The expected number of samples under the 2010 random 

sampling program (column F) is computed as the product of the number of samples in each volume class 

for the 2010 sampling program (column B) times the average E. coli percent positive in each volume 

class (column C). The expected number of samples under a sampling program based on the volume 

weighted percent positive in each volume class (column F) is computed as the product of the number of 

samples in each volume class for the E. coli volume weighted percent positive sampling program 

(column E) times the average E. coli percent positive in each volume class (column C). The odds of 

detecting an E. coli positive under the sampling program where the number of samples in each volume 

class is proportional to the volume weighted percent positive of the volume class are 1.5 times higher 

than under the current 2010 random sampling program. This is computed as the ratio of the expected 

number of E. coli positives under each sampling program (1.5 = 10.91/7.37). 

Table C- 5 Expected Number of Beef Trim E. coli Positives under Sampling Proportional to 

Volume Weighted Percent Positive 

(A) 

Volume 

Class 

(B) 

Percent 

of Total 

Volume 

(C) 

Average 

CY2007 

-June 

2011 

Percent 

Positive 

(D) 

Volume 

Weighted 

Percent 

Positive 

(VWPP) 

(E) 

Number of 

Samples 

Based on 

2010 

Random 

Sampling 

Program 

(F) 

Number of 

Samples 

Based on 

Sampling 

Proportional 

to VWPP & 

at Least 1 

Sample per 

Plant 

(G) 

Expected 

Positives 

Based on 

2010 

Sampling 

Program 

(H) 

Expected 

Positives 

Based on 

Sampling 

Proportional 

to VWPP in 

Volume Class 

Very 

Small 0.49% 0.42% 0.00% 915 4 3.84 0.02 

Small 6.48% 1.47% 0.10% 136 191 2.00 2.81 

Medium 24.12% 1.11% 0.27% 93 545 1.03 6.05 

Large 68.92% 0.38% 0.26% 130 533 0.49 2.03 

Total 100.00% 0.60% 0.60% 1,274 1274 7.37 10.91 

Table C-6 presents the expected number of beef trim E. coli O157:H7 positives resulting from sampling 

programs based on (1) the current (2010) sampling program which selects beef trim establishments at 

random and (2) a sampling program in which the number of samples in each volume class is 

proportional to the volume weighted percent positive of the volume class and each establishment is 

sampled at least once per year. The odds of detecting an E. coli positive under the volume weighted 

percent positive sampling program with at least one sample per establishment are 1.3 times higher than 

53 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

under the current 2010 random sampling program. This is computed as the ratio of the expected number 

of positives under each sampling program (1.3 = 9.66/7.37). 

Table C- 6 Expected Number of Beef Trim E. coli Positives under Sampling Proportional to 

Volume Weighted Percent Positive with at Least One Sample per Establishment 

(A) 

Volume 

Class 

(B) 

Percent 

of Total 

Volume 

(C) 

Average 

CY2007-

June 

2011 

Percent 

Positive 

(D) 

Volume 

Weighted 

Percent 

Positive 

(VWPP) 

(E) 

Number 

of 

Samples 

Based on 

2010 

Random 

Sampling 

Program 

(F) 

Number of 

Samples 

Based on 

Sampling 

Proportional 

to VWPP in 

Volume 

Class 

(G) 

Expected 

Positives 

Based on 

2010 

Sampling 

Program 

(H) 

Expected 

Positives 

Based on 

Sampling 

Proportional 

to VWPP in 

Volume 

Class 

Very 

Small 0.49% 0.42% 0.00% 915 292 3.84 1.23 

Small 6.48% 1.47% 0.10% 136 150 2.00 2.20 

Medium 24.12% 1.11% 0.27% 93 421 1.03 4.67 

Large 68.92% 0.38% 0.26% 130 412 0.49 1.56 

Total 100.00% 0.60% 0.60% 1,274 1274 7.37 9.66 

C-4 Probability of Detection of E. coli O157:H7 Positives under Increased Sampling Based on 

Seasonality 

Table C-7 presents the beef trim E. coli O157:H7 percent positive as a function of volume class for 

May-Oct and the rest of the year for CY2006 to June 2011. 

Table C- 7 Seasonality of Beef Trim E. coli Percent Positive 

Volume 

Class 

May-Oct 

E. coli 

Positives 

MayOct 

Total 

Tests 

May-Oct 

Percent 

Positive 

Rest of 

Year 

E. coli 

Positives 

Rest of 

Year 

Total 

Tests 

Rest of 

Year 

Percent 

Positive 

Very 

Small 11 1,864 0.59% 4 1,687 0.24% 

Small 9 305 2.95% 0 315 0.00% 

Medium 3 242 1.24% 2 210 0.95% 

Large 2 298 0.67% 0 231 0.00% 

Total 25 2,709 0.92% 6 2,443 0.25% 

54 
 

 

 

 

 

 

 

 

Table C-8 presents the expected number of beef trim E. coli O157:H7 positives resulting from sampling 

programs based on (1) the current (2010) sampling program which selects beef trim establishments at 

random and (2) a sampling program in which the number of samples in each volume class is 

proportional to the percent positive of the volume class and each establishment is sampled at least once 

per year and 60% of total samples are taken during May-Oct. The odds of detecting an E. coli positive 

under the percent positive sampling program with at least one sample per establishment and increased 

sampling during May-Oct are 2.0 times higher than under the current 2010 random sampling program. 

This is computed as the ratio of the expected number of positives under each sampling program (2.0 = 

14.57/7.37). 

Table C- 8 Expected Number of Beef Trim E. coli Positives under Sampling Proportional to E. coli 

Percent Positive with at Least One Sample per Establishment and 60% of Total Samples are 

Taken During May - Oct 

A) 

Volume 

Class 

(B) 

Number of 

Samples 

Based on 

2010 

Random 

Sampling 

Program 

(C) 

Number of 

Samples 

Based on 

E. coli 

Percent 

Positive 

Sampling 

& at Least 

1 Sample 

per Plant 

(D) 

Number of 

Samples If 

60% Taken 

During 

May-Oct 

(E) 

Number of 

Samples If 

40% Taken 

During Rest 

of Year 

(F) 

Expected 

Positives 

Based on 

2010 

Sampling 

Program 

(G) 

Expected 

Positives Based 

on Sampling 

Proportional to 

E. coli Percent 

Positive & at 

least 1 Sample 

per Plant & 

Increase 

Sampling 20% 

during May-Oct 

Very 

Small 915 292 175 117 3.84 1.31 

Small 136 488 293 195 2.00 8.64 

Medium 93 368 221 147 1.03 4.14 

Large 130 126 76 50 0.49 0.51 

Total 1,274 1,274 764 510 7.37 14.59 

55 
 

 

 

Appendix D - Procedures Codes 

FSIS inspectors perform inspection verification procedures to verify that establishments are executing 

their sanitation standard operating procedures (SSOP) and hazard analysis and critical control point 

(HACCP) system as specified under federal regulations 9 CFR 416 and 9 CFR 417. Table D-1 presents a 

summary of the 11 procedure codes considered in this study along with the associated health-related 

(W3NR) federal regulation numbers. 

Table D- 1 Procedure Code Description 

Procedure 

Code 

Description Associated Regulation Numbers 

01A01 Verify that establishment has met regulations for 

development or maintenance of sanitation standard 

operating procedures (SSOP) 

416.15(a), 416.15(b) 

01B01 Pre-operational review of establishment’s SSOP 310.22(b), 310.22(d)(2), 

records to verify daily documentation of 416.15(a), 416.15(b), 430.4(a), 

implementation and monitoring of SSOP procedures 430.4(b)(1), 430.4(b)(2), 

and required corrective actions. 430.4(b)(3) 

01B02 Pre-operational review and observation of SSOP 310.22(b), 310.22(d)(2), 

including implementation and monitoring, 416.15(a), 416.15(b), 416.4(d), 

maintenance, corrective actions, and recordkeeping. 430.4(a), 430.4(b)(1), 

Observe sanitation conditions; check one or more 

areas to ensure establishment is clean. 

430.4(b)(2), 430.4(b)(3) 

01C01 Review establishment’s operational SSOP records to

verify that the regulatory requirements for 

operational sanitation are met. Ensure monitoring 

activities are conducted at required frequency that the 

corrective actions are initiated to prevent direct 

contamination, and that records are being 

authenticated. 

01C02 The 01C02 procedure is for operational SSOP 310.22(b), 310.22(d)(2), 

verification. It is the same as the 01B02 procedure 416.15(a), 416.15(b), 416.4(d), 

except that it is conducted during operations. It 430.4(a), 430.4(b)(1), 

inspects one or more areas of the establishment to 

ensure procedures are effective in preventing direct 

contamination or other adulteration of product, 

observes the establishment perform the monitoring 

procedures, and compares finding to what the 

establishment has documented. 

430.4(b)(2), 430.4(b)(3), 

03A01 Determine establishment met regulation requirements 381.94(b)(3)(ii), 417.3(a)(1), 

for development and implementation of hazard 417.3(a)(2), 417.3(a)(3), 

analysis critical control point (HACCP) Plan(s) 417.3(a)(4), 417.3(b)(1), 

417.3(b)(2), 417.3(b)(3), 

417.3(b)(4), 417.3(c), 417.4(a), 

417.6 

03J01 Verify one or more HACCP requirements for 301.2(1)_Adulterated, 

monitoring, verification, and recordkeeping at a 301.2(1)_E.coli_O157:H7, 

slaughter establishment. The 03J01 procedure is 301.2(1)_L.monocytogenes, 

designed to provide a “snapshot” of the HACCP 301.2(1)_Salmonella, 

system. A 03J01 noncompliance necessitates 301.2(2)_Adulterated, 

performing a 03J02 procedure. FSIS Directive 301.2(3)_Adulterated, 

5000.1 301.2(4)_Adulterated, 

301.2(4)_Foreign_Material, 

56 
Procedure 

Code 

Description Associated Regulation Numbers 

301.2(6)_Adulterated, 

301.2(9)_Adulterated, 309.3, 

309.4, 309.9, 310.22(b), 

310.22(d)(2), 310.25(a), 

310.25(b), 311.16, 311.17, 

318.14(a), 381.1(i)_Adulterated, 

381.1(i)_E.coli_0157:H7, 

381.1(i)_L.monocytogenes, 

381.1(i)_Salmonella, 

381.1(ii)_Adulterated, 

381.1(iii)_Adulterated, 

381.1(iv)_Adulterated, 

381.1(iv)_Foreign_Material, 

381.1(vi)_Adulterated, 

381.144(a), 381.151(a), 

381.65(e), 381.83, 381.91(a), 

381.94(b)(3)(ii), 417.3(a)(1), 

417.3(a)(2), 417.3(a)(3), 

417.3(a)(4), 417.3(b)(1), 

417.3(b)(2), 417.3(b)(3), 

417.3(b)(4), 417.3(c), 417.4(a), 

417.6 

03J02 Verify all HACCP requirements at all critical control 301.2(1)_Adulterated, 

points in the HACCP establishment for a specific 301.2(1)_E.coli_O157:H7, 

production. Verify that the pre-shipment review 301.2(1)_L.monocytogenes, 

requirements for that specific production have been 301.2(1)_Salmonella, 

met. FSIS Directive 5000.1 301.2(2)_Adulterated, 

301.2(3)_Adulterated, 

301.2(4)_Adulterated, 

301.2(4)_Foreign_Material, 

301.2(6)_Adulterated, 

301.2(9)_Adulterated, 309.3, 

309.4, 309.9, 310.22(b), 

310.22(d)(2), 310.25(b), 311.16, 

311.17, 318.14(a), 

381.1(i)_Adulterated, 

381.1(i)_E.coli_0157:H7, 

381.1(i)_L.monocytogenes, 

381.1(i)_Salmonella, 

381.1(ii)_Adulterated, 

381.1(iii)_Adulterated, 

381.1(iv)_Adulterated, 

381.1(iv)_Foreign_Material, 

381.1(vi)_Adulterated, 

381.144(a), 381.151(a), 

381.65(e), 381.83, 381.91(a), 

381.94(b)(3)(ii), 417.3(a)(1), 

417.3(a)(2), 417.3(a)(3), 

417.3(a)(4), 417.3(b)(1), 

417.3(b)(2), 417.3(b)(3), 

417.3(b)(4), 417.3(c), 417.4(a), 

57 
Procedure 

Code 

Description Associated Regulation Numbers 

417.6 

04C04 Verify that poultry slaughter establishments comply 

with the relevant regulations for poultry finished 

product standards and good commercial practices for 

poultry slaughter 

381.1(i)_Adulterated, 

381.1(i)_E.coli_0157:H7, 

381.1(i)_L.monocytogenes, 

381.1(i)_Salmonella, 

381.1(ii)_Adulterated, 

381.1(iii)_Adulterated, 

381.1(iv)_Adulterated, 

381.1(iv)_Foreign_Material, 

381.1(vi)_Adulterated, 381.78, 

381.91(a) 

05A01 Review establishment E. coli records to determine 

maintained accuracy in accord with regulation—

verifies compliance with the basic regulatory 

requirements for E. coli testing in slaughter 

establishments. 

310.25(a), 310.25(b), 381.91(a) 

06D01 Verify compliance with Sanitation Performance 

Standards requirements -- addresses the manner in 

which establishments must be operated and 

maintained to prevent the creation of insanitary 

conditions, thereby ensuring that insanitary 

conditions are not created, and that product is not 

adulterated. 

310.22(b), 310.22(d)(2), 416.1, 

416.4(d) 

58