Dose-Response Modelling of Paralytic Shellfish Poisoning (PSP) in Humans.

Nathalie Arnich,Anne Thébault

doi:10.3390/toxins10040141

Nathalie Arnich, Anne Thébault

Open Access

https://doi.org/10.3390/toxins10040141

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Abstract

Paralytic shellfish poisoning (PSP) is caused by a group of marine toxins with saxitoxin (STX) as the reference compound. Symptoms in humans after consumption of contaminated shellfish vary from slight neurological and gastrointestinal effects to fatal respiratory paralysis. A systematic review was conducted to identify reported cases of human poisoning associated with the ingestion of shellfish contaminated with paralytic shellfish toxins (PSTs). Raw data were collected from 143 exposed individuals (113 with symptoms, 30 without symptoms) from 13 studies. Exposure estimates were based on mouse bioassays except in one study. A significant relationship between exposure to PSTs and severity of symptoms was established by ordinal modelling. The critical minimal dose with a probability higher than 10% of showing symptoms is 0.37 µg STX eq./kg b.w. This means that 10% of the individuals exposed to this dose would have symptoms (without considering the severity of the symptoms). This dose is four-fold lower than the lowest-observed-adverse-effect-level (LOAEL) established by the European Food Safety Authority (EFSA, 2009) in the region of 1.5 μg STX eq./kg b.w. This work provides critical doses that could be used as point of departure to update the acute reference dose for STX. This is the first time a dose-symptoms model could be built for marine toxins using epidemiological data.

Highlights

Paralytic shellfish poisoning (PSP) is caused by a group of marine biotoxins with saxitoxin (STX) as the reference compound
Since many individuals did not suffer adverse reactions at higher intakes it was expected that this LOAEL was close to the threshold for effects in sensitive individuals
This work provides critical doses that could be used as point of departure to update the acute reference dose (ARfD) for the Paralytic shellfish toxins (PSTs)

Summary

Introduction

Paralytic shellfish poisoning (PSP) is caused by a group of marine biotoxins with saxitoxin (STX) as the reference compound. More than 50 compounds have been reported [1]. Paralytic shellfish toxins (PSTs) are mainly produced by marine dinoflagellates of the genus. Alexandrium, e.g., A. tamarense, A. minutum, A. catenella, and by other dinoflagellates, such as Pyrodinium bahamense and Gymnodinium catenatum. PSTs are produced by freshwater cyanobacteria of the genera Anabaena, Cylindrospermopsis, Aphanizomenon, Planktothrix, and Lyngbia [1,2]. PSTs can accumulate in filter-feeding bivalve molluscs such as oysters, mussels, scallops, and clams from various parts of the world. The toxins generally do not cause any adverse effects in the shellfish (in some cases filtration behavior is affected), and do not give any colour or taste that could alert the consumer

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