Recent International Efforts to Improve Bivalve Molluscan Shellfish Safety

Abstract

Global trade in bivalve molluscan species has been increasing at a significant rate and in 2010; global production of molluscs (excluding fresh water molluscs and cephalopods) reached 14.6 million tonnes, of which 12.9 million tonnes came from aquaculture. Total bivalve trade has expanded continuously during the past three decades to reach US$ 2.1 billion in 2009. Scallops are the most important species accounting for 46 % of trade by value, followed closely by mussels (26 %). In terms of quantity, scallops accounted for 24 % of export, while mussels contributed to 48 %. FAO/WHO has been providing scientific support for Codex Committees working in bivalve molluscs and the ongoing work relates to Vibrio parahaemolyticus and V. vulnificus in oysters, norovirus, hepatitis A virus and biotoxins in bivalves. Considering that a risk management tool that is applicable over wide geographical areas would be very useful for pathogenic Vibrio spp., a tool based on FAO/WHO risk assessment for V. parahaemolyticus and V. vulnificus is being examined. Though shellfish harvesting is generally controlled using faecal indicator bacteria, there are concerns about the adequacy of this measure with respect of some pathogens such as viruses. There are also a number of concerns about the sampling plans required for detection of pathogens when the prevalence is very low and about the lack of internationally validated methods for some pathogens like V. parahaemolyticus and viruses. FAO/WHO initiatives to address these concerns and efforts made to build capacity in these areas and improve market access for bivalves from these countries is discussed in this paper.