Dar seafood ppp standard

Food safety risks due to molluscan shellfish

Oysters and other bivalves (excluding roe-off scallops)⁶⁴

The hazards potentially associated with oysters and other bivalves through the production and processing supply chain (Appendix 1) may be grouped as follows:

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  Endogenous bacteria that are human pathogens (Aeromonas hydrophila, V. parahaemolyticus, V. vulnificus, V. cholerae O1/O139, non-O1/non-O139 V. cholerae).
  
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  Pathogens introduced through pollution or post-harvest contamination (E. coli, S. aureus, Salmonella spp., Campylobacter spp., Shigella spp., Yersinia spp., L. monocytogenes, hepatitis A virus, Noroviruses).
  
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  Environmental chemical contaminants/toxicants (algal biotoxins, mercury, cadmium, arsenic, zinc).
  
  
  

The severity of illness due to these hazards (Table 3) ranges from moderate (for example, zinc, noroviruses), through serious (for example, L. monocytogenes, hepatitis A virus) to severe (for example, amnesic shellfish poison and paralytic shellfish poison algal biotoxins, V. cholerae O1/O139). Some of the hazards are considered severe only for certain susceptible populations (for example, L. monocytogenes, hepatitis A virus).
The likelihood of adverse health effects due to this broad range of hazards is diverse, ranging from unlikely through to very likely. Several large outbreaks of food-borne illness in Australia, attributed to oysters harvested from polluted waters that were not subject to the requirements of a comprehensive shellfish safety scheme such as the Australian Shellfish Quality Assurance Program (ASQAP), attest to the potential for significant adverse public health outcomes from the presence of these hazards in bivalve molluscs [19].
Oysters and other bivalves are considered a food group that is occasionally eaten by a significant proportion of the population (Appendix 3; [7,9]) and, on this basis, evidence of the potential for a hazard to be present at an infectious or toxigenic level at the point of consumption is taken as the main determinant of the likelihood of adverse health effects for the general population.
The likelihood of adverse health effects due to each of the hazards identified in Appendix 1 is discussed briefly below.