Quarterly Progress Report on Salmonella Testing of Selected Raw Meat and Poultry Products: Preliminary Results, October - December, 2006
Attachments to this report:
Increasing the testing frequency in establishments that exhibit highly variable or variable process control. New criteria for scheduling Salmonella sets were implemented for sets scheduled from June 2006 onwards. (Visit FSIS' Web site at http://www.fsis.usda.gov/pdf/scheduling_criteria_salmonella_sets.pdf (PDF Only) to view these.) These new criteria focus FSIS resources on establishments with the most samples positive for Salmonella and the most samples with serotypes most frequently associated with human salmonellosis. While these new criteria are preliminary in nature and will be continually reassessed and modified when needed, the overall objective of a risk-based approach to verification sampling remains constant.
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). The results for the 1,016 turkey carcass samples collected October-December 2006 are presented (Table 1).
Posting quarterly results to the FSIS Web site. This is the fourth such report, covering October-December 2006. Data are presented in three formats:
- Percent positive Salmonella tests by product class and establishment size. Table 1 summarizes all fourth-quarter samples in the same format used in past annual reports.
- Proportion of establishments in each of the three categories identified in February Federal Register Notice. Given the revised testing strategy, the percentage of positive samples is no longer useful as an indicator of trends, and so FSIS is considering alternative trend indicators for the Salmonella verification program. Tables 2, 3, and 4 detail the proportion of establishments in each of the three categories identified in February Federal Register Notice, using broiler (young chickens), market hog and cow/bull establishments as examples. The largest proportions of establishments are in Category 1 as of December 31, 2006: 49% of broiler establishments (table 2); 55% of market hog establishments (table 3); and 55% of cow/bull establishments (table 4). Note: The February 2006 FR Notice stated a goal of having 90% of establishments in Category 1 after one year under the revised sampling system.
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 product classes will be added to future quarterly reports as appropriate data are available, and other trend indicators continue to be considered.
- Salmonella results summarized by product class for the most recent five quarters. NOTE: While the first two 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 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 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. This is the third quarter for turkey testing; therefore, only three bars appear on this graph. In some cases the relatively small number of samples collected can result in seemingly large changes from quarter to quarter. For example, the apparent jump from 7.4% to 24.2% Salmonella positives in ground turkey from the third to the fourth quarter only represents a change from 2 of 25 samples collected that tested positive for Salmonella in the third quarter, to 8 of 33 that tested positive in the fourth quarter.
Annual reports summarizing results for calendar years will continue to be available on the FSIS Web site. (FSIS is also considering posting results by fiscal year). 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 scheduled to begin shortly, and additional baseline studies are under development.