Publication Abstract

Diarrhetic Shellfish Poisoning toxins: the story behind a recent case of human intoxication in the UK

L.Coates*, B.Stubbs*, S. Morris*, C. Brunet*, Sarah Swan and M.Algoet*

In June 2006, a human intoxication incident was reported to have occurred in London, affecting 171 individuals that had consumed mussels at several restaurants. Symptoms were described as ”resembling those of Diarrhetic Shellfish Poisoning or norovirus intoxication” and were reported to have occurred within 2-12 h of the meal.

The three batches of mussels responsible for the incident were identified as originating from a Scottish classified shellfish production area routinely monitored for the presence of marine biotoxins under the scope of the official control monitoring programme delivered by the Food Standards Agency Scotland.

Laboratory analyses conducted on mussels obtained from the restaurants showed that whilst norovirus could not be detected in the samples, lipophilic toxins were present at levels above the regulatory limit. Data from the intoxication incident and the Scottish biotoxin monitoring programme was reviewed to establish the chronology of events which led to contaminated shellfish reaching the consumer. Investigations showed that the toxic event had developed quickly. The area had been monitored 10 days prior to the harvesting of contaminated mussels and monitoring had shown no indication of risk. The following routine sample, collected on the same day as the last batch of contaminated mussels, confirmed that a toxic incident due to Dinophysis sp was underway.

This paper provides a summary of the incident and shows how follow up investigations allowed a better understanding of the conditions leading to the intoxication and how recent changes to biotoxin sampling regimes reduce the risk of non-detection of toxic episodes.