A semi-quantitative seafood safety risk assessment.

As part of a semi-quantitative risk assessment of 10 seafood hazard/product combinations, a risk assessment tool was used to generate a Risk Ranking. The tool is in a spreadsheet software format and provides a risk estimate, which is scaled between 0 and 100, where 0 represents no risk and 100 represents all meals containing a lethal dose of the hazard. A full description of the tool is contained in Ross and Sumner (this issue). Based on their ranking, seafoods in Australia fell into three risk categories. Hazard/product pairs with ranking < 32 included mercury poisoning (Relative Risk = 24), Clostridium botulinum in canned fish (RR = 25), or in vacuum-packed cold-smoked fish (RR = 28), parasites in sushi/sashimi (RR = 31), viruses in shellfish from uncontaminated waters, (RR = 31), enteric bacteria in imported cooked shrimp (RR = 31) and algal biotoxins from controlled waters (RR = 31). It is noted that there have been no documented cases of food-borne illness from any of the above hazard/product pairings in Australia. Those with rankings 32-48 included Vibrio parahaemolyticus in cooked prawns (RR = 37), V. cholerae in cooked prawns (RR = 37), Listeria monocytogenes in cold-smoked seafoods (RR = 39), scombrotoxicosis (RR = 40), V. vulnificus in oysters (RR = 41), ciguatera in the general Australian population (RR = 45), L. monocytogenes in susceptible (RR = 45) and extremely susceptible populations (RR = 47) and enteric bacteria in imported cooked shrimp eaten by vulnerable consumers (RR = 48). Almost all the hazard/product pairs in this category have caused the outbreaks of food poisoning in Australasia. Those hazard/product pairs with rankings >48 included ciguatera from recreational fishing in susceptible areas (RR = 60), viruses in shellfish from contaminated waters (RR = 67) and algal biotoxins from uncontrolled waters in an algal event (RR = 72). There have been significant (>100 cases) food poisoning incidents involving viruses and biotoxins in shellfish, while ciguatera poisoning is prevalent among coastal communities in Australia's warmer waters.