Results for Serotyping of Salmonellae from Meat and Poultry Products: July–December 2007
All tables and figures are available in the PDF version of this document (pp. 3-26).
The Food Safety and Inspection Service (FSIS) issued the Pathogen Reduction; Hazard Analysis and Critical Control Point (PR/HACCP) Systems, Final Rule on July 25, 1996: Federal Register, Vol. 61, No. 144, pp. 38805-38989 (http://www.fsis.usda.gov/OPPDE/rdad/FRPubs/93-016F.pdf , PDF Only). The PR/HACCP rule sets Salmonella performance standards for establishments that slaughter or produce selected classes of food animals or raw ground products. Under PR/HACCP, performance standards were established for carcasses of cows/bulls, steers/heifers, market hogs, broilers, ground beef, ground chicken, and ground turkey based on nationwide microbiological baseline studies conducted before the rule was implemented. In June 2006, FSIS began sampling turkey carcasses for Salmonella. Guidance on turkey carcass levels can be found in the Federal Register, Vol. 70, No. 32, pp. 8058-8060 (http://www.fsis.usda.gov/OPPDE/rdad/FRPubs/02-046N.htm | PDF).
Prior to 2006, there were two phases of the FSIS regulatory program for Salmonella in raw products: non-targeted and targeted testing. Non-targeted or "A" set samples were collected at establishments randomly selected from the population of eligible establishments with a goal of scheduling every eligible establishment at least once a year. Other codes (such as "B", "C", and "D") represented sample sets collected from establishments targeted for follow-up testing following a failed set. FSIS replaced the targeted/non-targeted approach with risk-based scheduling in 2006. The serotype data here are from all sample sets.
In February 2006, FSIS announced in the Federal Register, Vol. 71, No. 38, pp. 9772-9777, (http://www.fsis.usda.gov/OPPDE/rdad/FRPubs/04-026N.htm | PDF) that quarterly results from Salmonella verification testing would be posted and that the Agency would provide individual test results to establishments before completion of a set. The Agency has published quarterly Salmonella results since 2006 (http://www.fsis.usda.gov/Science/Q3_2007_Salmonella_Testing/index.asp ; http://www.fsis.usda.gov/Science/Q4_2007_Salmonella_Testing/index.asp).
In June 2006, FSIS developed new criteria for scheduling establishments (http://www.fsis.usda.gov/Science/Scheduling_Criteria_Salmonella_Sets/index.asp | PDF) that are risk-based and designed to focus FSIS resources on establishments that have the most samples positive for Salmonella and the greatest number of samples with serotypes most frequently associated with human salmonellosis as defined by the Centers for Disease Control and Prevention (CDC) (http://www.cdc.gov/ncidod/dbmd/phlisdata/salmonella.htm). Establishments are no longer randomly selected under the new criteria. The collection of serotype data is not designed for trend analysis. One of the goals of the revised risk-based program is to identify the source of serotypes of the greatest human health concern and to report those findings directly to establishments as they become available. FSIS also now ensures that all pathogens of public health concern are identified regarding both their subtype (serotype and PFGE pattern) and their drug resistance profiles.
The number of isolates of each serotype, the percent of isolates out of total positive, and the percent of isolates of total samples collected are displayed in Tables 1-8 (July through September of the 3rd Quarter) and Tables 9-16 (October through December of the 4th Quarter).
The ten most commonly isolated serotypes for each product class during each quarter are identified by name. Less commonly identified serotypes are included in the "other serotypes" category. When there is more than one serotype in tenth place, all serotypes in tenth place are listed.
The tables include entries classified as "unidentified" isolates. A single, specific serotype could not be determined for these isolates.
Figures 1-8 display the percent of isolates identified out of total isolates serotyped for each product class by quarter from July 2005 forward for the top eight serotypes associated with human illness in 2007 (for consistency in the graphs, data collected prior to the 2006 revisions was updated to include results from all sets) (http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5614a4.htm?s_cid=mm5614a4_e ).
For Figures 1-8, the y-axis, representing the serotype percentage, varies from graph to graph because the incidence of different serotypes by commodity varies greatly and year-to-year variations in percentages are difficult to discern on one scale of high value.
FSIS can not determine how the revised Salmonella testing program affects the distribution of serotypes from positive samples. Thus, comparisons of results from 2006 onward to previous years are inappropriate. Similarly, the changes to the verification program 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) and Turkey Baseline Studies are currently in progress, and additional baseline studies are under development.
Salmonella verification testing is conducted to establish regulatory compliance (http://www.fsis.usda.gov/Science/Scheduling_Criteria_Salmonella_Sets/index.asp | PDF), not to establish prevalence of either Salmonella or specific serotypes of Salmonella. Data reported here are not intended to be reflective of national trends in prevalence of serotypes.
Tables and Figures (pp. 3-26 in the PDF version of this report.)