Microbiological Criteria for Raw Molluscan Shellfish

Abstract

The recommendations are designed to enhance the microbiological safety profile of raw molluscan shellfish which are likely to present inherent risks to consumers if adequate safeguards are not in place from harvest to consumption. Further, the document examines the “wholesale market standard” currently applied by the Interstate Shellfish Sanitation Conference (ISSC). Product testing alone is of limited value in assuring the safety of molluscan shellfish. For a market standard to be useful, it must be used as one of several control strategies. The recommendations are as follows:* Proper growing water classification and restriction of harvesting to those water areas are two of the most essential points in controlling both enteric pathogens of human origin and indigenous vibrios in molluscan shellfish. Without proper water classification and harvesting, any market standard applied would have a minimal effect on consumer protection.* Time/temperature control and monitoring during product distribution are essential to assure safety. Rapid cool down and continuous product chilling are also essential. When various combinations of warm harvest water and air temperatures exist, harvest requirements necessitating additional measures to assure rapid chilling should be implemented. In instances where this cannot be accomplished within a prescribed time, area closure may be necessary.* Minimize the introduction and multiplication of bacteria in molluscan shellfish during distribution through adequate sanitation and refrigeration requirements.* The Food and Drug Administration should develop a specific interpretation of the retail model code for HACCP-based control of raw molluscan shellfish to include purchase specification of properly tagged and refrigerated product.* The ISSC should incorporate the recommendations contained in this report into a revised National Shellfish Sanitation Program (NSSP) Manual of Operations and reissue the document as the Shellfish Sanitation Model Ordinance for adoption into state law. Further, the current “wholesale market standard” should be changed to include a modified aerobic plate count procedure which encourages the growth of Vibrio spp.* Fecal coliform/Escherichia coli should be retained as a guideline until state regulatory agencies are provided adequate assurance that all products have been harvested from properly classified growing waters. In the future, additional criteria may be appropriate if the National Indicator Study proposes changes in water classification standards.* The NSSP Manual should be expanded to include strict control measures from harvest through retail distribution.* Education programs can contribute to reducing risks associated with the consumption of raw molluscan shellfish. This is a shared responsibility of government and industry. These recommendations were adopted by the National Advisory Committee on Microbiological Criteria for Foods on July 18, 1991.