Between 2016 and 2021, the Canadian Food Inspection Agency (CFIA) collected 4218 samples of fresh and frozen berries (blackberries, blueberries, raspberries, strawberries and mixed berries) and pomegranate arils at retail across 11 major cities in Canada and tested these samples for the presence of norovirus GI, norovirus GII and hepatitis A virus RNA. The purpose of this testing was to provide information on the prevalence of these viruses in berries and pomegranate arils on the Canadian marketplace. Of the 926 fresh fruit samples tested, norovirus GI RNA was detected in one raspberry sample and norovirus GII RNA was detected in one strawberry sample. Of the 3292 frozen fruit samples tested, norovirus GI RNA was detected in one blackberry sample, one raspberry sample and one strawberry sample, and norovirus GII RNA was detected in one blueberry sample, three raspberry samples, four strawberry samples, one pomegranate arils sample and one mixed berry sample. None of the fresh or frozen fruit samples tested positive for hepatitis A virus RNA. No statistically significant associations were observed between the prevalence of viral RNA in samples of fresh and frozen fruit, between the prevalence of viral RNA in samples of domestic and imported fruit or between the prevalence of viral RNA in samples of specific fruit types. Overall, the prevalence of norovirus GI and GII RNA together in fresh and frozen fruit samples in Canada was 0.36 %. The results of this study may be used to refine surveillance programs for norovirus and hepatitis A virus in fresh and frozen berries and pomegranate arils, e.g. by adapting the commodities tested and/or the numbers of planned samples to better target these hazards. This information may also be used to inform other Government of Canada approaches to better understand the controls associated norovirus and hepatitis A virus in fresh and frozen berries and pomegranate arils.

A profile of the microbial safety of cheese in Canada was established based on the analysis of 2955 pasteurized and raw-milk cheeses tested under Canada's National Microbiological Monitoring Program (NMMP) and 2009 raw-milk cheeses tested under the Targeted Survey Program. 97.8% of NMMP and 99.6% of Targeted Survey cheese samples were assessed as being of satisfactory microbiological safety. Under the NMMP, Salmonella spp. was detected in 2 samples, Listeria monocytogenes was detected in 15 samples and no Escherichia coli O157/H7:NM (non-motile) was detected. Cheese samples assessed as having unsatisfactory levels of S. aureus and generic E. coli were found in 18 and 41 samples, respectively. Under the Targeted Survey, L. monocytogenes was detected in 2 samples, while no Salmonella spp. or E. coli O157/H7:NM were detected. Cheese samples assessed as having investigative and unsatisfactory levels of S. aureus were found in 4 and 2 samples respectively. No samples were found to have investigative or unsatisfactory levels of generic E. coli. For cheese samples collected under the NMMP, logistic regression models indicated that contamination was more frequent in raw-milk cheeses compared to pasteurized-milk cheeses (OR = 5.0, 95% CI (3.0, 8.3)), and in imported cheeses compared to domestic cheeses (OR = 8.2, 95% CI (4.1, 16.1)). A statistically significant association was found between cheese samples assessed as having unsatisfactory levels of generic E. coli and detection of L. monocytogenes, Salmonella spp. or levels of S. aureus that were assessed as unsatisfactory (p < .001). These test results will help support risk analysis and inform food safety decisions.

Following two O121 Shiga toxin-producing Escherichia coli (STEC) outbreaks linked to wheat flour, this study was conducted to gain baseline information on the occurrence of bacterial pathogens and levels of indicator organisms in wheat flour in Canada. A total of 347 prepackaged wheat flour samples were analyzed for Salmonella species, STEC, Listeria monocytogenes, aerobic colony count (ACC), total coliforms, and Escherichia coli. Salmonella spp. and O157 STEC were not detected in any of the samples. L. monocytogenes was identified in two samples (0.6%) at levels below the limit of detection (<0.7 log CFU/g). Non-O157 STEC were isolated from six samples (1.7%) and were characterized for the presence of STEC virulence genes: stx(1), stx(2), and their subtypes, eae, hlyA, and aggR. One O103:H25 STEC isolate carried virulence genes (stx(1a)+eae) that are known to be capable of causing diarrhea and/or bloody diarrhea in humans. Of the five remaining non-O157 STEC isolates, four carried single stx(2a) or stx(2c) genes and were considered to have the potential of causing diarrhea. The remaining non-O157 STEC isolate (stx(2)), while not a priority non-O157 STEC, was not available for sequencing; thus, its potential to cause illness is unknown. ACC, total coliforms, and E. coli were detected (>= 0.48 log CFU/g) in 98.8, 72.6, and 0.6% of the flour samples. The mean counts of ACC were greater in whole wheat flour compared with the other flour types tested (P < 0.001). The results of this study suggest that the occurrence of O157 STEC and Salmonella is low but that the occurrence of non-O157 STEC in wheat flour with the potential to cause human illness of diarrhea is relatively common. Therefore, the consumption of raw flour could increase the likelihood of STEC infections. Further research is merited for potential risk mitigation strategies within the food production system and with consumers.

A national baseline study was conducted between December 2012 and December 2013 to determine the pre-packaging prevalence and concentration of foodborne pathogens on broiler chicken carcasses and parts at processing; a survey was implemented simultaneously to collect data on the processing practices used to control these pathogens. Thirty federally-registered Canadian poultry processing establishments completed the questionnaire. A total of 2,732 samples of carcasses and parts (breast and thigh pieces) were collected over the study period from these establishments. For Salmonella, the overall proportion positive was 0.22 (95% CI 0.20, 0.23), and the mean concentration was 0.67 (95% CI 0.51, 0.83) MPN/mL of rinse fluid. Multivariable regression models with random intercepts for the establishment and the date of sampling were used to identify associations between Salmonella prevalence and concentration and processing practices. In the final logistic regression model for the prevalence outcome (positive or negative sample), there were three statistically significant variables: product type (carcass or part); chilling method (water or air); and chlorine use in the establishment (chlorine, cetylpyridinium chloride, or neither). The likelihood of testing positive for Salmonella was higher on parts than carcasses (OR 3.03, 95% CI 2.38, 3.86), and higher when cetylpyridinium chloride was used (OR 2.00, 95% CI 1.36, 2.95), or when other processing aids were used (OR 1.99, 95% CI 1.26, 3.15), than when chlorine was used. Water chilling was negatively associated with testing positive for Salmonella when compared with air chilling (OR 0.68, 95% CI 0.48, 0.96). In the final linear regression model for the concentration outcome (log10 MPN/mL), there was one statistically significant variable chilling method, where water chilling was associated with a decrease in concentration (β -0.23, 95% CI -0.38, -0.08 log10 MPN/mL). The intraclass correlation coefficients for establishment and date sampling were 0.02 and 0.23 in the linear regression model, and 0.01 and 0.34 in the logistic regression model, respectively. Further studies to explore the methods to reduce microbial contamination during the air chilling and cut-up and boning processes in broiler chicken establishments in Canada are recommended.