Dual system to boost marine biotoxin detection in shellfish

But the safety watchdog has suggested retaining use of the mouse bioassay in conjunction with the chemical test to provide a more comprehensive safety net for the detection of toxins in shellfish. The agency said the less precise mouse assay gives a more global view of possible sources of toxins, while the chemical equivalent gives a very specific and detailed analysis of known toxins.

AFSSA said its dual approach would “make it possible to anticipate the consequences of atypical toxicities that would not be fully assessed using regulatory monitoring”.​

​

Chemical test​

The French body made its announcement in the wake of a call by the European Food Safety Authority (EFSA) in September 2009 to replace the flawed mouse assay with a chemical test for detection of the 13 lipophilic marine biotoxins in shellfish.

AFSSA said its new chemical assay was validated last summer. The validation came after a long-term research project carried out by the body’s national reference laboratory (NRL) in conjunction with the European reference laboratory. A methods comparison test to verify the comparability of initial results was completed during the second half of 2009 by the NRL and the French Research Institute for Exploitation of the Sea (Ifremer).

“Within the context of the expected regulatory modifications, the agency has acquired the equipment and manpower needed for immediate implementation of the chemical test method for official shellfish analyses prior to commercialisation”,​ said an AFSSA statement.

Safety boost​

The agency also proposed a system to use both the new chemical testing regime in partnership with the mouse assay - which it said would boost shellfish safety.

The chemical test provides more detailed analysis and reliable detection of the lipophilic toxins but only within a “predetermined list of chemical substances, making it impossible to detect possible emerging toxins or new analogs of known toxins”,​ it said.

The mouse assay should be maintained – but with a modified frequency of use – as an additional safeguard to provide very early detection of emerging sources of toxicity to humans, and not just the 13 currently regulated toxins, added the body.

AFSSA said: “This would provide data for a safeguard unit that could supply additional investigations, warning measures and/or management measures in certain cases, especially in the event of a positive mouse test result unexplained by chemical analysis.”​

The system could be rapidly modified to take into account the risk related to phycotoxins produced by various species of Ostreopsis found on the Mediterranean coast.

“This combination of monitoring and safeguarding will mean that both the chemical tests and the mouse bioassay will be used to their fullest advantage”,​ said the agency.