Assessing the effectiveness of performance standards for Salmonella contamination of chicken parts.

The United States Department of Agriculture's Food Safety and Inspection Service implemented Salmonella performance standards for establishments producing chicken parts in 2016. The standards were chosen based on the assumption that a 30 % reduction in the occurrence of Salmonella-contaminated chicken parts samples (i.e., legs, breasts or wings) would result following implementation of the performance standard program. The derivation of the performance standards was based on data collected prior to the implementation of the standards and in the intervening years, so overall changes in the Salmonella contamination of this product can be assessed. This study presents a historical review of changes in Salmonella contamination on chicken parts as these changes relate to the performance standard. The analysis demonstrates that the reduction in Salmonella contaminated chicken parts samples was more than 75 %, so the FSIS risk assessment significantly underestimated the actual reduction in Salmonella contamination. An analysis of chicken parts samples collected at retail demonstrates reductions of a similar magnitude. Changes in the characteristics of Salmonella contamination that are potentially relevant to the occurrence or severity of human illness, such as seasonal changes in contamination, the composition of serotypes and changes in antimicrobial resistance, are also assessed. Small but significant seasonal increases in contamination were observed, with the peaks occurring in late winter rather than the more traditional late summer peak. Rapid changes in both the five most common serotypes and antimicrobial resistance patterns were also observed.

Occurrence of Salmonella in Ready-to-Eat Meat and Poultry Product Samples from U.S. Department of Agriculture-Regulated Producing Establishments. II. Salmonella in Ready-to-Eat Pork Barbecue Products, from 2005 to 2012.

Ready-to-eat (RTE) meat and poultry product samples from the random ALLRTE and risk-based RTE001 sampling projects of the Food Safety and Inspection Service (FSIS) were tested for both Listeria monocytogenes and Salmonella. In the course of analyzing Salmonella data for calendar years 2005 to 2012, it was observed that 8 (17.0%) of 47 positive samples were from pork barbecue. The eight Salmonella-positive samples, from seven establishments in a single state, were from 1,085 pork barbecue samples tested nationwide (0.74% positive) and from 296 samples tested from that one state (2.7% positive). The seven establishments represented 30.4% of 23 federal establishments in that state that had pork barbecue samples tested for Salmonella. A follow-up sample from intensified verification testing at one of the seven establishments also was positive for Salmonella. Upon further examination, contamination appeared to be influenced by regional differences in production methods. Notably, the style of pork barbecue that tested positive for Salmonella used a vinegar- and pepper-based sauce in which the ingredients were mixed without cooking. All the establishments with Salmonella-positive samples followed the practice of first cooking the pork and then adding the barbecue sauce ingredients (vinegar, pepper, other spices, etc.) after cooking (postlethality exposure). In addition to the sauce ingredients, other possible sources of contamination included employee hygiene and food handling practices and cross-contamination from other Salmonella-contaminated products and from commonly used equipment. Based on these findings, the FSIS issued guidelines recommending changes in production methods that would minimize or eliminate pork barbecue as a potential source of foodborne Salmonella infections.

Survey of polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans and non-ortho-polychlorinated biphenyls in US meat and poultry, 2012-13: toxic equivalency levels, patterns, temporal trends and implications.

The US Department of Agriculture (USDA) conducts a statistically based survey of the domestic meat supply (beef, pork, chicken and turkey) to determine current levels of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and non-ortho-polychlorinated biphenyls (no-PCBs) every 5 years. Fat samples for each slaughter class were collected from US federally licensed slaughter facilities. The samples were processed and analysed for 17 PCDD/Fs and three no-PCBs. The sum of PCDD, PCDF and no-PCB toxic equivalencies (sum-TEQ) calculated using 2005 toxic-equivalency factors for all slaughter classes ranged from non-detect (n.d.) to 6.47 pg TEQ g-1 lipid. The median sum-TEQs, when n.d. = 0.5 LOD, for beef, pork, chicken and turkey were 0.66, 0.12, 0.13 and 0.34 pg TEQ g-1 lipid respectively. A comparison of the current survey with the previous three surveys shows a declining trend, with decreasing differences between medians; differences between the median sum-TEQs from 2007-08 and 2012-13 were -10%, -29%, -33% and -25% for beef, pork, chicken and turkey respectively. Several beef samples underwent further characterisation and congener patterns from these beef samples suggested pentachlorophenol treated wood as the likely exposure source. US consumer exposure to these compounds is relatively low and no slaughter class contributed more than 26% to the US Environmental Protection Agency (USEPA) chronic oral reference dose of 0.7 pg TEQ kg-1 bw day-1.

Survey of polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans, and non-ortho-polychlorinated biphenyls in U.S. meat and poultry, 2007-2008: effect of new toxic equivalency factors on toxic equivalency levels, patterns, and temporal trends.

A statistically based survey of dioxins and dioxin-like compounds in domestic meat and poultry was conducted by the U.S. Department of Agriculture (USDA) from September 2007 to September 2008. Seventeen toxic polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and four non-ortho-polychlorinated biphenyls (no-PCBs) were measured in 510 beef (steer/heifer), market hog, young turkey, and young chicken samples. The results of the survey showed the sum of PCDD/F and no-PCB toxic equivalencies (sum-TEQs) ranging from not detected to 4.5 pg/g of lipid. Mean sum-TEQ levels for beef, turkey, chicken, and pork were 0.66, 0.61, 0.17, and 0.16 pg/g of lipid, respectively. To compare the new survey data with data from previous USDA surveys in the mid-1990s and 2002-2003, TEQs from all data sets were calculated using the most recent 2005 toxic equivalency factors (TEFs). The results of the recalculation on the older survey data was a small increase (4-13%) in mean TEQs for the mid-1990s data, which initially used pre-1994 TEFs, and a small decrease (2-4%) for the 2002-2003 data, which initially used 1998 TEFs. A comparison of the three surveys indicates declining TEQ trends in all slaughter classes over the 10 year period; however, the congener patterns remain relatively constant between 2002 and 2008, indicating similar animal exposures to dioxins and dioxin-like compounds during these time periods. Several samples from the 2008 survey with the highest TEQ values are undergoing follow-up investigations to determine possible sources that may be contributing to these levels.

Statistically designed survey of polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans, and co-planar polychlorinated biphenyls in U. S. meat and poultry, 2002-2003: results, trends, and implications.

To obtain information on dioxin levels in the human diet, the Food Safety and Inspection Service of the United States Department of Agriculture recently determined levels of dioxin-like compounds (dioxins/dibenzofurans/PCBs) in four major slaughter classes (steers and heifers, market hogs, young chickens, and young turkeys) that comprise over 90% of the meat and poultry production in the United States. The data were analyzed and compared to data from smaller surveys carried out from 1994 to 1996. These surveys were conducted by different laboratories nearly 10 years apart, so a direct comparison of the data was not straightforward. Three approaches were taken: (1) comparison with nondetects set to zero, (2) comparison with nondetects set to half the limit of detection, and (3) comparison applying the earlier surveys' limits of detection to the newer data. The data analyses indicated that dioxin levels appear to have declined in three of the four slaughter classes, with young chickens, market hogs, and young turkeys declining 20-80%, while any declines in cattle dioxin levels, if real, are less than those observed in the other slaughter classes. Further study is needed to examine factors that might explain the differences in dioxin levels and distribution profiles in the four slaughter classes. A small number of market hog and steers/ heifers samples had dioxin toxic equivalency levels (TEQs) greater than 2 pg/g lipid weight. Follow-up investigations for those samples indicated a common source for the market hog samples (a dioxin-contaminated mineral supplement), but no commonality was found for the steers/ heifers samples.