Paralytic shellfish poisoning (PSP) is a world-wide, sometimes fatal seafood poisoning caused by potent algal neurotoxins that accumulate in shellfish. Most nations have certified shellfish PSP testing programs required for international commerce. The accepted international method for PSP testing is the mouse bioassay. To replace live animal testing we developed a PSP receptor binding assay (RBA) technique. Rigorous validation of the RBA method resulted in international acceptance.

Why We Care
Globally, over 2000 people are affected by PSP each year. Because we cannot control naturally occurring algae that produce the PSP toxins, the monitoring of shellfish growing waters and the testing of commercially harvested shellfish are essential to protect public health. This requires many thousands of tests to be run annually. Yet, the use of live animal testing has become increasingly unacceptable. Replacement of the mouse test for regulatory testing is therefore an important goal.

What We Did
We conducted an international collaborative study of the RBA for PSP in shellfish through the Association of Official Analytical Chemists (AOAC), an international professional organization that certifies testing methods for food, agriculture, and pharmaceutical products.  The study, which included nine laboratories from five nations, assessed the reproducibility of test results between laboratories and compared the performance of the RBA with the existing regulatory mouse bioassay. The RBA was deemed to perform as well as the existing method, and was accepted by the AOAC as an Official Method of Analysis.

Next Steps
The recognition of the method as an AOAC Official Method provides the validation criteria necessary to be considered for regulatory use. The method is currently being submitted jointly by the Food and Drug Administration and NOAA to the Interstate Shellfish Sanitation Conference for recognition as a regulatory method. This would allow the method to be used for interstate commerce of shellfish in the US.  Similar measures will be pursued for recognition in the EU, a major global importer of shellfish.