Bacterial Pathogens and Indicators in Ready-to-Eat Fish and Seafood – April 1, 2018 to March 31, 2021
Food microbiology – Targeted surveys – Final report
A 3-year targeted surveyFootnote 1 analysed 1165 samples of ready-to-eat (RTE) fish and seafood, and their products for the presence of the pathogens Listeria monocytogenes (L. monocytogenes), Salmonella species (spp.), and Staphylococcus aureus (S. aureus). All samples were also tested for generic Escherichia coli (E. coli) which is an indicator of the hygienic and sanitary conditions of the food supply chain from production to the point of sale.
Over 98.9% of the samples tested were found to be satisfactory. Salmonella spp., S. aureus (> 103 CFU/g) and generic E. coli (> 102 CFU or MPN/g) were not found in any of the samples tested. L. monocytogenes was found in 12 of the 1165 (1.0%) samples. The Canadian Food Inspection Agency (CFIA) conducted appropriate follow-up activities. There were no reported illnesses related to these products.
Overall, our survey results indicate that RTE fish and seafood samples sold in Canada are generally safe for consumption, however they can occasionally be contaminated. Consequently, as with all food, and especially those that are ready for consumption without further preparation or cooking, good hygienic practices are recommended for producers, retailers and consumers.
Why was this survey conducted
The survey was conducted to provide enhanced oversight of the quality and safety of RTE fish and seafood, and their products sold at retail in Canada. The RTE fish and seafood product types sampled under this survey included fish (smoked, cured, dried), seafood (shrimp, crab), and fish and seafood products (mousse, pâté) which are all commonly consumed by CanadiansFootnote 2. Unfortunately, many of these foods have been associated with recallsFootnote 3, Footnote 4, and foodborne illness outbreaksFootnote 5, Footnote 6 and are considered high-risk foodsFootnote 7.
Contamination with bacterial pathogens can occur at any step in the food supply chain such as during production, harvest, post-harvest handling, processing, distribution and/or at retail. When consumed, the presence of pathogens creates the potential for foodborne illness.
When was the survey conducted
The survey was conducted over a 3-year period from April 1, 2018 to March 31, 2021. Refrigerated products were collected throughout the survey period while frozen products were only collected during the last 2 years of the survey.
Where were the samples collected from
Samples were collected from national retail chains and local/regional grocery stores located in the following 11 major cities across Canada:
- Quebec City
- Victoria or Kelowna
The planned number of samples to be collected from each city was based on the population of the province in which the city was located relative to the total population of Canada.
How many and what kind of samples were collected
A total of 1165 pre-packaged RTE fish and seafood samples were collected of which 636 were fish, 310 were imitation crab or lobster, 126 were seafood (other than fish) and 93 were fish and seafood products. A sample consisted of a single or multiple consumer sized packages of the same lot weighing at least 250g.
What were the samples tested for
All samples were tested for L. monocytogenes, Salmonella spp., S. aureus and generic E. coli. L. monocytogenes, Salmonella spp., and S. aureus are pathogenic bacteria while generic E. coli is an indicator of the overall hygienic and sanitary conditions under which the samples have been processed, stored and transported.
What methods were used to test the samples
Samples were analyzed using analytical methods published in Health Canada's Compendium of Analytical Methods for the Microbiological Analysis of FoodsFootnote 8 that were suitable for the testing of RTE fish and seafood.
How were samples assessed
The samples were assessed using criteria based on the principles of the CFIA's Canadian Hazards Guide – Fish and Fish ProductsFootnote 9, Health Canada's Policy on Listeria monocytogenes in Ready-to-Eat FoodsFootnote 10 and guidelines developed by international food safety authoritiesFootnote 11, Footnote 12.
|L. monocytogenes||Not detected||Not applicable (Category 1 Table Note a)
Detected and ≤ 102 CFU/g (Category 2 Table Note a)
|Detected (Category 1 Table Note a)
>102 CFU/g (Category 2 Table Note a)
|Salmonella spp.||Not detected||Not applicable||Detected|
|S. aureus||≤ 103 CFU/g||> 103 and ≤ 104 CFU/g||> 104 CFU/g|
|Generic E. coli||≤ 102 CFU or MPN/g||> 102 and ≤ 103 CFU or MPN/g||> 103 CFU or MPN/g|
What were the survey results
Over 98.9% of the samples tested were found to be satisfactory. Salmonella spp., S. aureus (> 103 CFU/g) and generic E. coli (>102 CFU or MPN/g) were not found in any of the samples tested. L. monocytogenes was found in 12 of the 1166 (1.0%) samples at levels of < 5 CFU/g.
|Bacteria||Number of samples tested||Satisfactory (%)||Investigative (%)||Unsatisfactory (%)|
|L. monocytogenes||1165||1153||6 Table Note b||6 Table Note c|
|Salmonella spp.||Not applicable||0|
|Generic E. coli||0||0|
|Total||1165||1153 (99.0)||6 (0.5)||6 (0.5)|
Survey results are also presented by origin (table 3) and product type (table 4).
|Product origin||Number of samples tested (%)||Satisfactory||Investigative||Unsatisfactory|
|Unknown Table Note d||113 (9.7)||111||1||1|
|Unknown Table Note d (domestically processed) Table Note e||409 (35.1)||403||3||3|
|Product type||Number of samples tested (%)||Satisfactory||Investigative||Unsatisfactory|
|Fish (smoked, salted, dried, fermented)||636 (54.6)||624||6 Table Note f||6 Table Note g|
|Fish and seafood products (caviar, mousse, pâté)||93 (8.0)||93||0||0|
|Seafood (other than fish) (lobster, shrimp, octopus, crab, mussels)||126 (10.8)||126||0||0|
|Imitation crab or lobster||310 (26.6)||310||0||0|
What do the survey results mean
Previous CanadianFootnote 13 studies on the microbial quality and safety of retail RTE fish and seafood products have shown results approximating those in our study while internationalFootnote 14, Footnote 15 studies have shown higher prevalence rates. Differing prevalence rates between studies may be attributable to differences in product types tested, methodology, study design, etc.
Overall, our survey results indicate that RTE fish and seafood sold in Canada are generally safe for consumption, however they can be infrequently contaminated. Consequently, as with all foods, and especially with those that are ready for consumption without further preparation or cooking, good hygienic practices are recommended for producers, retailers and consumers.
What is done with the survey results
All results are used to:
- inform risk management decisions
- support program design and re-design
While no illness were related to the investigative and unsatisfactory samples, these results triggered appropriate follow-up actions including:
- facility inspections
- additional sampling and testing
- removal of affected products from the marketplace
Can I access the survey data
Yes. The data will be accessible on the Open Government Portal.
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