Paralytic shellfish poisoning is a foodborne marine-toxin syndrome that arises after consuming shellfish contaminated with saxitoxins generated by dinoflagellates [1]. The responsible paralytic shellfish toxins block voltage-gated sodium channels and are produced by marine dinoflagellates as well as freshwater cyanobacteria [1][2].
Disease overview
Other Evidence-backed information EN 3/7 applicable sections · ZH 3/7 applicable sections Updated Oct 23, 2026
Paralytic shellfish poisoning is a foodborne marine-toxin syndrome linked to saxitoxin-contaminated shellfish and is documented across temperate and other coastal regions worldwide [1]. It represents an underrecognized hazard for travelers and is associated with expanding harmful algal blooms and changing climate conditions [1].
Read the full clinical and epidemiological profile 4
Affected individuals may develop gastrointestinal, neurologic, cardiovascular, or respiratory effects of varying severity [1]. Symptom onset is generally 30–60 minutes after ingestion of toxic shellfish but may be delayed several hours [1]. Severe presentations can include ataxia, paralysis, respiratory failure, or death [1].
The syndrome occurs globally, with notable reporting from temperate waters off Atlantic and Pacific North America including Alaska, and additional cases across the Americas, Asia, Europe, Australia, and New Zealand [1]. Global distribution maps indicate affected coastal regions concentrated along North America, Europe, Southeast Asia, Australia, and Pacific Islands [1]. Contributing pressures such as harmful algal bloom spread, international trade, tourism, and rising seafood consumption are increasing the public-health risk [1].
- 1 US Centers for Disease Control and Prevention. Food Poisoning from Marine Toxins | CDC Yellow Book⢠[Internet]. cited 23 Oct 2026. Available from: https://www.cdc.gov/yellow-book/hcp/environmental-hazards-risks/food-poisoning-from-marine-toxins.html
- 2 Raposo MIC et al. Paralytic Shellfish Toxins (PST)-Transforming Enzymes: A Review. Toxins (Basel). 2020 May 22. PMID: 32456077. doi: 10.3390/toxins12050344. PubMed: https://pubmed.ncbi.nlm.nih.gov/32456077/
- T61.2
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