. Author manuscript; available in PMC: 2016 Sep 9.

Published in final edited form as: Harmful Algae. 2016 Jul;57(B):2–8. doi: 10.1016/j.hal.2016.05.003

Table 1.

Seafood Intoxications

Syndrome (Major Toxin)	Vectors (Known and Potential)	Onset Time and Duration	Major Symptoms	Treatment	Prevention
Ciguatera Fish Poisoning^a (Ciguatoxin)	Large, predatory tropical reef fish (barracuda, grouper, red snapper, amberjack); some types of eels; farm-raised fish that feed on contaminated fish.^b	12 to 24 hours; neurological symptoms can last months to years	n, v, d, ab, p (especially hands and feet), t, bp. Also: metallic taste, itching, dizziness. Possible recurrence of neurological symptoms during times of stress, after ingesting alcohol or low level fish. Low mortality in the US.^c,d,e	Supportive. Mannitol therapy is recommended for neurological symptoms.^f Brevenal has also been indicated.^g	Avoid consuming risky fish; education about avoiding consumption of the viscera especially where reef fish are a key subsistence source^h; monitoring; illness surveillanceⁱ
Diarrhetic Shellfish Poisoning^j,k,l (Okadaic Acid)	Mussels, oysters, scallops, clams, cockles, some species of crabs ^m,ⁿ,^o	30 minutes to 15 hours; full recovery, within 3 days^m	d (incapacitating), n, v, ab. Headache, fever. No reported mortality.	Supportive. Most people do not seek medical treatment.	Monitoring seafood and water; regulated in European countries, though outbreaks still occur^p
Neurotoxic Shellfish Poisoning^q (Brevetoxins)	Mussels, clams, whelks, conch, coquinas, oysters, scallops; liver and stomach contents of some planktivarous fish; inhalation of toxin aerosolized by coastal wind and waves^q,r	Consumption: A few minutes up to 18 hours (often within 3-4 hours) Inhalation: Minutes to hours (<24 hours)	Consumption: p (perioral, face, extremities), ab, t, d, b, r (most severe cases). May appear disorientated or intoxicated (slurred speech, pupil dilation, overall fatigue, involuntary muscle spasms). Inhalation: a, b, r. Throat irritation, sneezing, coughing, itchy and watery eyes, burning of upper respiratory tract. No reported mortality for either pathway’s	Consumption: Supportive. Inhalation: Leave the beach and go to an air-conditioned area.	Coastal and seafood monitoring and quarantine; clear, easily available information on recreational closures^s,t; persons with asthma or respiratory problems should avoid beaches during “red tides.”
Paralytic Shellfish Poisoning^u,v,w (Saxitoxins)	Scallops, mussels, clams, geoducks, cockles, puffer fish, some fish, gastropods, crustaceans ^x	30 minutes to 3 hours; a few hours to a few days	p (perioral, often spreading to neck and extremities), n, v, r (severe doses: respiratory paralysis and death). Muscular weakness, drowsiness, incoherent speech. No mortalities in recent US and European outbreaks.	Supportive. Artificial ventilation in severe cases.	Coastal monitoring; quarantine of seafood and region; rapid case reporting; beach closures to recreational harvester^y
Amnesic Shellfish Poisoning^z,aa (Domoic Acid)	Razor clams, mussels, oysters, squid. Viscera (not muscle) of scallops, sardines, anchovies, crab, and lobster.^bb	Within 48 hours; months to years with permanent amnesia.	ab, n, v, r, disorientation, seizures, permanent short-term memory loss, possible neurodevelopmental delay. Excessive respiratory secretions.^cc Coma and death only among most severe cases^y or elderly.^bb	Supportive.	Coastal monitoring of water and shellfish; harvesting beach closures; rapid illness reporting

Abbreviated symptoms: a, allergic-like; ab, abdominal cramps; b, bronchoconstriction; bp, decrease in blood pressure; d, diarrhea; n, nausea; p, parathesias; r, respiratory distress; t, reversal of temperature sensation; v, vomiting