Surveillance des risques biologiques liés à la consommation de coquillages en France

Shellfish filter large volumes of water to meet their nutritional requirements and thus ingest phytoplankton, but also concentrate microorganisms naturally present in water (vibrios, phycotoxins) or of fecal origin (enteric viruses, enterobacteria, protozoan). The analysis of data from systems contributing to the surveillance of foodborne illnesses associated with shellfish consumption and from published outbreak investigations shows that, in France, foodborne illnesses associated with shellfish consumption are mainly of viral origin, mostly due to norovirus followed by hepatitis A virus. The risk linked to phycotoxins appears low and the one related to enterobacteria and vibrios very low. The mandatory notification (MN) of foodborne outbreaks remains the most effective system for the surveillance and detection of health effects associated with shellfish consumption. MN could be enhanced in shellfish growing areas, by increasing its completeness by the mean of raising awareness among potentially notifying persons, and by increasing the quantity and quality of investigations. In terms of prevention, the environmental and shellfish monitoring suitable for bacterial and phycotoxinic risks could be reinforced by a preventive approach to fecal contamination. This approach could be based primarily on securing the sanitation system and also on sharing information allowing to suspect or anticipate environmental contamination among concerned partners so that sellfish safety measures could be implemented by shellfish farmers.