Quarterly Progress Report on Salmonella Testing of Selected Raw Meat and Poultry Products: Preliminary Results, October – December, 2007
Attachments to this report:
In February 2006, FSIS announced several changes | PDF to the Salmonella Verification Testing Program in order to implement a risk-based approach for verification sampling. These changes include:
Increasing the testing frequency in establishments that exhibit highly variable or variable process control. To view these criteria, visit FSIS' Web site at http://www.fsis.usda.gov/Science/scheduling_criteria_salmonella_sets/index.asp | PDF.
Testing of turkey carcasses. The guidance document "Generic E. coli and Salmonella Baseline Results," which specifically addressed turkeys ( http://www.fsis.usda.gov/OPPDE/rdad/FRPubs/02-046N.htm | PDF) (February 17, 2005 Federal Register Notice (70 FR 8058)) specified a maximum of 13 positive samples in a set of 56 samples. That guidance was based on results from the turkey carcass sponge baseline study conducted from July 1997 through June 1998 ( http://www.fsis.usda.gov/PDF/Baseline_Data_Young_Turkey.pdf, PDF Only).
Posting quarterly results to the FSIS Web site. This is the fourth report for CY 2007, covering October-December 2007. Quarterly reports for CY 2006 can be accessed at: http://www.fsis.usda.gov/Science/Quarterly_Salmonella_Results/index.asp .
Data for this report are presented in three formats:
- Percent positive Salmonella tests by product class and establishment size. Table 1 summarizes all 2007 fourth quarter samples in the same format used in past quarterly and annual reports.
- Proportion of establishments in each of the three categories for quarters 1 - 4 CY 2007 identified in the 2006 February Federal Register Notice.
Given the revised testing strategy, the percentage of positive samples is no longer useful as an indicator of trends. Therefore, FSIS has implemented an alternative trend indicator for the Salmonella verification program.
As one of the new initiatives in the February 2006 Federal Register notice, FSIS outlined how establishments will be categorized based on Salmonella set performance. Establishments are now placed in one of three categories to reflect their level of process control. In order to be placed in category 1, an establishment must show consistent process control by having two consecutive sets at less than or equal to 50% of the performance standard or guidance for its product class. An establishment that has completed only one set (without exceeding the performance standard or guidance) or has one or both consecutive Salmonella sets at greater than 50% of the performance standard or guidance for its product class without exceeding it, is considered to have variable process control and placed in category 2. An establishment that fails a set demonstrates highly variable process control and is placed automatically in category 3. This would include an establishment that has only completed one set if that set failed to meet the existing performance standard or guidance.
(NOTE: These protocols for categorizing establishments have been consistently used for the quarterly and annual summaries published since the February 2006 Federal Register Notice. See the quarterly report for January-March, 2007 for information clarifying both the (1) footnotes that have accompanied the previous summaries, and (2) criteria for counting and categorizing establishments. This report, and all future reports, will categorize establishments using the definition for total number of establishments as those establishments that are currently operating and subject to sampling that have at least one completed set.)
Using broiler (young chickens), market hogs, turkey, and cow/bull establishments as examples, tables 2, 3, 4, and 5 detail the proportion of establishments in each of the three categories. As of December 31, 2007, 77% of broiler establishments (table 2); 69% of market hog establishments (table 3); 87% of turkey establishments (table 4) and 65% of cow/bull establishments (table 5) were in category 1.
While the Agency does not expect this trend indicator to vary greatly on a quarterly basis, it should facilitate tracking of overall industry performance when examined over multiple years. Other trend indicators continue to be considered.
- Salmonella results summarized by product class for the most recent five quarters. NOTE: While earlier quarterly reports included individual sample results from "A" sets only, this report and future reports will summarize data from all sets. This change was discussed in the 2006 second quarterly report which can be accessed on the FSIS Web site: http://www.fsis.usda.gov/science/Q2_2006_Salmonella_Testing/index.asp .
In this revised format the results for each product class are shown in a graph (PDF Only) depicting the number of samples and the percentage of positive samples by quarter for the last five quarters. Graphs for all product classes are included, recognizing that the number of samples can be very small, even zero, for some products in a specific quarter.
Annual reports summarizing results for calendar years will continue to be available on the FSIS Web site. However, the restructuring of Salmonella set scheduling means that comparison of results from 2006 onwards to previous years will be inappropriate. Similarly, the changes to the verification program will prevent valid comparisons of testing results over time (e.g., quarter-to-quarter or year-to-year trends). For such comparisons, the results of upcoming nationwide baseline studies can be used to provide valid estimates of the prevalence of certain pathogens of public health concern and permit valid statistical comparisons to be made over time. A 12-month Young Chicken (Broiler) Baseline Study is currently in progress, and additional baseline studies are under development.