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g SEAFOOD SAFETY 



Principal Conclusions 



• Most seafood-associated illness is reported from consumers of raw bivalve 

 molluscs, and is due to unknown etiologies but is clinically suggestive of Norwalk- 

 like viral gastroenteritis. The majority of incidents are due to consumption of shellfish 

 from fecally polluted water. The disease is usually mild and self-resolving. 



• Naturally occurring marine Vibrio species are responsible for fewer reported 

 cases of infection from the consumption of raw molluscan shellfish, but species such 

 as V. vulnificus can be associated with high monality in persons who are 

 immunocompromised or who have underlying liver disease. 



• A lesser risk of microbial disease associated with other seafoods -resulting 

 from recontamination or cross-contamination of cooked by raw product, or to 

 contamination from other sources -is usually associated with time/temperature abuse. 

 The etiologic agents most commonly involved, in order of reported frequency, are V. 

 parahaemotyiicus, hepatitis A, Salmonella, Shigella. Clostridium perfringens. and C. 

 boiulinum (mostly limited to Alaskan natives). 



• Seafood-related parasitic infections are even less common than bacterial and 

 viral infections, with anisakids and cestodes having the greatest public health 

 significance in the United States. In general, parasitic infections have resulted from 

 consumption of raw or partially cooked fresh- and saltwater fish of particular species 

 (e.g., whitefish, salmon). 



Principal Recommendations 



• Consumers should be informed of the risks of eating raw seafoods, 

 particularly molluscan shellfish. Individuals belonging to high-risk groups, such as 

 cirrhotics, people with hemochromatosis, or immunosuppressed individuals, must not 

 eat raw shellfish; this requires that health professionals be educated concerning hazards 

 to high-risk individuals. 



• Adequate and proper treatment and disposal of sewage must be implemented 

 to avoid contamination of harvest areas by human enteric pathogens. 



• Valid indicators for human pathogen contamination of growing waters must 

 be developed. Seafood-borne infections by human enteric viruses in raw and 

 improperly cooked molluscan shellfish could be decreased significantly by the 

 development of valid growing water indicator(s) and of direct detection methodologies 

 for enteric viruses. 



• Effective enforcement to eliminate recreational commercial and illegal 

 harvesting and sale of molluscan shellfish from contaminated growing areas should be 

 developed and adequately funded. 



• Means must be investigated and implemented to eliminate, or at least reduce, 

 levels of potentially pathogenic Vibrio species in raw shellfish. This may necessitate 

 restriction of harvest when water temperatures are high, rapid cool-down and continued 

 chilling of products, and possibly irradiation of live shellstock and shucked products. 



• Consideration should be given to monitoring Vibrio counts in molluscan 

 shellfish during warm months. 



• Because of the high risks associated with raw molluscan shellfish, the 

 importation of live shellfish for raw consumption should not be permitted unless 



