| Histamine (Scombroid) Poisoning: background | - first recognized from ingestion of spoiled scrombroid group fish (tuna, mackerel, bonito); other types of fish have been linked to this type of poisoning (mahi-mahi, bluefish, marlin, escolar)
- high level of free histidine in fish tissue
- rapid growth of bacteria during temperature abuse of fish
- bacteria convert the histidine to histamine via histidine decarboxylase enzyme
- bacteria ex: Morganella, Klebsiella, Proteus spp. Enterobacter
- FDA action level for histamine: 500 ppm in fish |
| Histamine (Scombroid) poisoning: symptoms | - gastrointestinal
- neurological
- cutaneous
- hypotension
- symptoms occur rapidly (within 1 hr)
- disease not fatal |
| Histamine (Scombroid) poisoning: prevention strategies | - cold storage of fish soon after catching
- proper cleaning and sanitation of fish contact surfaces
- histamine is heat stable!!
- avoid temp abuse of fish
- avoid consumption of suspect fish |
| Ciguatera poisoning | - in carnivorous finfish (barracuda, grouper, seabass)
- > 50,000 cases occur globally every year
- ciguatera toxin (ciguatoxin)
- produced by toxic dinoflagellates in coral reefs in tropical and subtropical waters
- toxin accumulates in fish through the food chain
- high concentration in fish liver, intestines, roe (eggs), and head
- symptoms develop within a few hours |
| Dinoflagellates | - group of flagellated marine plankton that ause Ciguatera poisoning
- some are photosynthetic
- many are mixotrophic (combination photosynthesis with ingestion of prey) |
| Ciguatera poisoning symptoms | - gastrointestinal: nausea, vomiting, diarrhea, abdominal pain
- neurological: tingling feeling in lips/fingers, itching, loose teeth sensation, metallic taste, blurred vision |
| Ciguatera poisoning: detection | - no method currently exists
- avoid consumption of large reef fish, particularly the inner organs |
| Paralytic Shellfish poisoning | - shellfish: clams, scallops, mussels
- toxin produced by toxic algae (Gonyaulax catanella, Alexandrium catanella) that shellfish feed on, accumulates in tissue
- several toxins can cause paralytic shellfish poison (Saxitoxin)
- short incubation period, symptoms within 1hr of consumption
- toxin is heat stable, not destroyed by cooking
- sporadic occurrence, depends on growth of toxic algae |
| Paralytic shellfish poisoning: symptoms | - neurological: tingling and numbness of lips/face/finger tips, drowsiness, poor coordination, incoherent speech, dry throat, respiratory failure
- gastrointestinal: headache, nausea, vomiting, diarrhea
- death in extreme cases |
| Toxic algae bloom influencing factors | - water temperature (~8 C)
- salinity
- run-off and presence of nutrients |
| Algae causing paralytic shellfish poisoning | Gonyaulax catanella, Alexandrium catanella |
| Histamine (Scombroid) poisoning bacteria | Morganella, Klebsiella, Proteus spp. Enterobacter
- decarboxylate histidine into distamine |
