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September 28, 1998

Pathogen Reduction/HACCP Salmonella Performance Testing


Thomas Billy


Kaye Wachsmuth


PR/HACCP Salmonella Performance Testing


August 28, 1998

The Office of Public Health and Science (OPHS) has completed an analysis of data from the Salmonella testing program, 6 months after the implementation of HACCP in 178 large meat and poultry plants. We have compared their compliance phase Salmonella prevalence (2/1/98 through 7/31/98) with pre-implementation phase prevalence (6/1/97 through 1/31/98) and with baseline prevalence data. We've also reviewed large plant compliance with Salmonella performance standards. These data signal significant initial progress in our pathogen reduction efforts.

This is an innovative new program and strategy, without precedent; therefore, OPHS scientists have taken a conservative approach in interpreting and presenting the data. We have confidence in the quality and stability of the data presented. We have excluded information on a number of meat and poultry products, because there are too few data points in each category. Although the overall industry pathogen reduction performance is good, it could be misleading to suggest measurable improvements on the basis of only one or two plants in a species or product category.

We did look at aggregate data for all species categories without regard to complete sample sets, at prevalence data per plant, at compliance data also without regard to completed sets, and at pre-implementation data for the small and very small meat and poultry plants. We also calculated the standard deviation and coefficient of variation for the summary data.

One of the main difficulties with the Salmonella sampling program has been the paucity of accurate business information on the industry. Since 1979, a series of Federal paperwork reduction efforts has eliminated mandatory industry reporting systems and affected the quantity and quality of production and other data available to FSIS. The Office of Field Operations has worked to re-establish industry information bases, and we began to see a marked improvement toward the end of 1997. The small and very small plant information is improving also, but there are still some problems with categorizing plants and obtaining the appropriate samples.

After February 1, 1999, we will issue a more complete report on the first year of large plant HACCP sampling and testing. We will also try to include pre-implementation phase Salmonella data for small and very small plants at that time.

Attached for your review is the 6 month report. Any comments or suggestions are welcome.


Catherine Woteki
Mark Mina
Maggie Glavin
Patricia Stolfa


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Progress Report: Pathogen Reduction Performance Standards for Salmonella

Six months after implementation of HACCP in large meat and poultry plants, most plants, for which sample sets have been completed, are in compliance with Salmonella pathogen reduction performance standards. The number of plants and samples at 6 months is too small for generalizations across industry. However, summary data indicate a general trend toward lower percentages of Salmonella positive product as compared to baseline prevalence and HACCP pre-implementation data.

Products covered by the HACCP large plant compliance testing program include cattle, swine, and broiler carcasses and ground beef, ground chicken, and ground turkey. Baseline data to establish performance standards for turkey carcasses and ground pork were not available before HACCP implementation in January, 1998. Therefore, no compliance data have been collected to date. Standards have since been determined, and rule making has been initiated.

Salmonella Summary Data

Table 1 describes Salmonella data for swine and broiler carcasses. Only these species categories contained at least 10 completed sample sets in the first 6 months of testing, i.e., a set = 55 for swine, and a set = 51 for broilers. (A more complete explanation of sample sets will follow.) Ten sample sets were chosen as a conservative threshold to better ensure relatively stable statistical analyses. The 95% confidence intervals around Salmonella prevalence are narrow for both swine and broiler data.

Table 1 indicates progress toward pathogen reduction with the introduction of SSOPs in 1997 and HACCP in 1998 for large plants. The percentage of Salmonella positive products for both swine and broilers was lower in pre-implementation testing than baseline prevalence surveys and lowest in HACCP plants. This signals important initial progress in our pathogen reduction efforts.

We would like to indicate that other species categories appear to be performing well in the HACCP environment. Although the data did not meet criteria for inclusion in the table, ground beef HACCP data (8 complete sample sets) are also below both the baseline and pre-implementation Salmonella prevalence.

Finally, we acknowledge that caution should be used in making direct comparisons of the summary data included in Table 1:

Baseline surveillance data, upon which Salmonella performance standards were calculated, represent a true industry prevalence. Data are production-based, were collected over an entire year, and represent 99% of production in each species category. The 6 months of HACCP pre-implementation and compliance phase data do not meet these criteria and were generated using a different sample frame. (Of note: Large broiler plant representation of production is closer to the baseline 99% than would be the case for any type of livestock.)

Pre-implementation data were collected June 1, 1997 to January 31, 1998, while actual HACCP compliance data were collected February 1, 1998 to July 31, 1998. This means that pre-implementation data do not span an entire year and represent the summer months, which are potentially associated with a higher prevalence of pathogens on products.

The number of plants varies between pre-implementation and HACCP phase of testing. Some plants that were originally considered large during pre-implementation testing eventually qualified as small plants and vice versa. As the quality of information on plant size and product improves, FSIS is adjusting the sampling frames accordingly.

Compliance with Salmonella Performance Standards

Table 2 describes the total number of meat and poultry plants with completed sample sets as defined in the PR/HACCP Final Rule [9 CFR 310.25 (b) (1) and 381.94 (b) (1)]. The actual performance standard was calculated from the baseline percent positive and is expressed as the number of samples to test (n) and the number of positives to allow from among those samples (c). Standards were calculated to provide an 80% probability of passing when the establishment is operating at the national baseline prevalence of positive Salmonella results.

Table 2 indicates that after 6 months of HACCP compliance phase Salmonella testing, 88% of large plants have met the standard. Plants failing to meet the performance standard were formally notified and required to take immediate action to come into compliance with the PR/HACCP Rule [9 CFR 310.25 (b) (3) (i) and 381.94 (b) (3) (i)].

Although Table 2 contains a small number of plants and small numbers per species category, there is overall good conformance to Salmonella performance standards. The broiler data are particularly strong, representing over half of the total number of large plants.

Incomplete compliance data sets are not included here, but 33 of 38 sets with predictable outcomes will pass, comparable to data in Table 2, i.e., 87% compared with 88%.

Finally, we analyzed percentage positive Salmonella data per plant for poultry and swine. Not only did 53 of 60 poultry plants meet the standard, 40 of the 53 had a Salmonella prevalence of less than 10%. Similarly, not only did 8 of 10 swine plants meet the standard, all 8 had a prevalence below 5%. In other words, the majority of plants in compliance are actually at levels below summary data presented in Table 1.

Again, a conservative view of the current compliance data indicates progress in pathogen reduction efforts.

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Table 1: Summary Data from Salmonella Testing in Large Swine and Broiler Plants 




Number of plants





Number of samples





Percent Positive





National Baseline Prevalance*



 Products represent those for which at least 10 sample sets have been completed, as defined in the Pathogen Reduction; Hazard Analysis and Critical Control Point Systems; Final Rule, July 25, 1996 (FR Vol. 61, No. 144, p. 38847).

* Percent positive.

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Table 2: Large Plant Compliance with HACCP Salmonella Performance Standards










Ground Beef



Ground Turkey









This table shows large plants during HACCP/Compliance phase (2/1/98 - 7/31/98) that completed a full sample set, as defined in the Pathogen Reduction; Hazard Analysis and Critical Control Point Systems; Final Rule, July 25, 1996 [9 CFR 310.25(b)(1) and 381.94(b)(1)].

For Further Information Contact:
FSIS Office of Public Health and Science
1400 Independence Ave. SW
Room 341-E JLW Bldg.
Washington, DC 20250-3700
Phone:  (202) 720-2644
FAX:  (202) 690-2980

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URL: http://www.fsis.usda.gov/ophs/salmstd.htm
Last Updated On 09/28/98.