Seafood Toxins Seafood Toxins Dr. Robert Price has retired & - PDF document

Seafood Toxins Seafood Toxins � Dr. Robert Price has retired & died. Seafood Toxins Seafood Toxins � Excerpts from the US FDA “Bad Bug Book” PHR 250 � Order of presentation is according to my perception of relative risks in the US. Selected Illnesses Selected Illnesses Shellfish-associated Shellfish-associated toxins toxins � Shellfish-associated toxins � Paralytic Shellfish Poisoning (PSP) � Scombroid poisoning � Diarrheic Shellfish Poisoning (DSP) � Ciguatera poisoning � Neurotoxic Shellfish Poisoning (NSP) � Tetrodotoxin (pufferfish) � Amnesic Shellfish Poisoning (ASP) Paralytic SP Paralytic SP Saxitoxin (PSP) � PSP, predominantly neurological (tingling, burning, numbness, drowsiness, incoherent speech, and respiratory paralysis) � Onset in 0.5 – 2 hr, death from respiratory or circulatory failure 1

Paralytic SP Paralytic SP Diarrheic SP Diarrheic SP � Mussels, clams, cockles, & � Mild GI disorder (nausea, scallops vomiting, diarrhea, & � Detecting PSP toxins abdominal pain with chills, (saxitoxin, etc.): mouse headache, and fever) bioassay or HPLC � Onset 0.5 – 2 or 3 hr, lasts � Beach “postings” (language) ≤ 3 days, complete recovery Okadaic acid (DSP) Diarrheic SP Diarrheic SP � Mussels, oysters, & scallops � Detecting DSP toxin (okadaic acid): mouse bioassay unreliable; HPLC or ELISA used (plus others) Neurotoxic SP Neurotoxic Brevetoxin (NSP) � GI & neurological symptoms: tingling & numbness of lips, tongue, & throat, muscular aches, dizziness, reversal of the sensations of hot & cold, diarrhea, & vomiting � Onset mins–hrs, duration hrs– days, complete recovery 2

Neurotoxic SP Neurotoxic Amnesic SP Amnesic SP � GI disorders (vomiting, � Shellfish harvested along diarrhea, abdominal pain) & Florida coast & Gulf of Mexico neurological problems � Detecting NSP toxin (confusion, memory loss, (brevetoxin): no method disorientation, seizure, coma); mentioned serious (sometimes fatal) in elderly Domoic acid (ASP) Amnesic SP Amnesic SP � GI onset ≤ 24 hr, neurological onset ≤ 48 hr, long-term neurological effects � Mussels � Detection of ASP toxin (domoic acid) by HPLC Scombroid Scombroid Poisoning oisoning Scombroid Scombroid Poisoning oisoning � Tingling or burning in � Onset immediate – 0 min, mouth, rash on upper body, duration ~ 3 hr (rarely, drop in blood pressure. several days) � Frequently, headache & � May progress to nausea, itching skin vomiting, & diarrhea 3

Scombroid Scombroid Poisoning oisoning Scombrotoxin precursor � Hospitalization (elderly or impaired patients)? � [ Mimics allergy .] Scombroid Scombroid Poisoning oisoning Ciguatera Ciguatera � Tunas (e.g., skipjack & � Combination of GI (nausea, yellowfin), mahi mahi, vomiting, diarrhea), bluefish, sardines, mackerel, neurological (perioral amberjack, & abalone; other numbness & tingling, may foods — Swiss cheese spread to extremites), & � FDA test for histamine (other cardiovascular disorders toxins may also be involved) Ciguatera Ciguatera Ciguatoxin � Onset ≤ 6 hr; lasts days, weeks, months (years), relapses possible � Warm-water marine finfish: groupers, barracudas, snappers, jacks, mackerel, triggerfish (sporadic) 4

Ciguatera Ciguatera Tetrodotoxin Tetrodotoxin � Slight numbness of lips & � Ciguatera toxins difficult to tongue at 20 min – 3 hr extract & purify; mouse � Increasing paraesthesia, bioassay may be replaced face & extremities; by EIA sensations of lightness or � Diagnosis only! floating Tetrodotoxin Tetrodotoxin Tetrodotoxin Tetrodotoxin � Possible headache, epigastric � Increased paralysis, convulsions, pain, nausea, diarrhea, mental impairment, cardiac arrhythmia vomiting (reeling or difficulty in walking) � Victim (completely paralyzed?) may be conscious & completely � 2d stage: increasing paralysis, lucid until shortly before death dysphonia, dyspnea, cyanosis, (at 4–6 hr, range 20 min–8 hr) and hypotension Tetrodotoxin Tetrodotoxin Tetrodotoxin � Pufferfish from Indo-Pacific ocean regions (~ 20 spp., toxin distributions differ — gonads, viscera, skin � Testing: mouse PSP bioassay; HPLC & GC/MS methods await validation 5

7 seafood poisonings 7 seafood poisonings � Transient: DSP, NSP, (ASP), scombroid (ciguatera) � Life-threatening: PSP, ASP (elderly), tetrodotoxin � Prevention: PSP, monitoring; scombroid, product care; tetrodotoxin, knowledge + skill 6