He can’t fly this plane, he had the fish for

dinner!

DisclosuresNone

Goals

• Define common seafood poisonings• Delve into their histories• Describe the toxicology• Explain their treatment

Ciguatera

• Most common nonbacterial food poisoning• Estimated incidence 20-50K/year

• Algal bloom related• Gambierdiscus toxicus

• Benthic and reef predatory fish• Barracuda, snapper, grouper,

amberjack

• Viscera and roe have highest concentrations

History

• Name comes from cigua• Spanish common name for a snail

• Recognized since ancient times• 9th century BC-Homer’s Odyssey

• 7th century BC-Chinese outbreak

• 4th century BC-Alexander the Great refused to allow soldiers to eat fish

• Possibly caused Polynesian migration

• 1530-First definitive reference• De Orbe Novo by Peter Martyr d'Anghiera

• 1774-Captain Cook• 1789-Captain Bligh

Toxicology

• 4 Major toxins• Ciguatoxin• Maitotoxin• Scaritoxin• Palytoxin

• Heat stable• Activate voltage dependent

sodium channels• Sustained depolarization

Symptoms

• Onset• Minutes to Hours

• GI• N/V/D/abdominal cramps

• Neurologic• Headache• Myalgias• Paresthesias• Allodynia• Metallic taste

• Cardiac• Hypotension• Bradycardia

• Seizure• Coma• Death• Can cause long term disability

Treatment

• Decontamination• Symptomatic Care• Atropine• Sodium channel blockers• Lidocaine• Amitryptiline

• CCBs• Nifedipine

• Mannitol

Here it gets weird

• Flies are supposed not to land on contaminated fish• Cats will display symptoms after

eating contaminated fish• Putting a silver coin under the

scales of the suspect fish• If it turns black fish is contaminated

• Place a piece of the fish on the ground and allow ants to crawl on it • If ants continue to move then the fish

is safe

• Reports of sexual transmission• Might be transmitted in breast

milk

Scombroid

• Pseudoallergenic fish poisoning• Estimated at 40% of all seafood-

borne illness• 2-31/1,000,000• 703 patients in US 1998-2002

• Scombridae• Albacore, bluefin, yellowfin,

skipjack, mackerel, wahoo

• Non Scombridae• Mahi-mahi, black marlin,

amberjack

• Swiss cheese

History

• First reported in 1830• Edinburgh Medical and Surgical

Journal, Volume 34

History

• First reported in 1830• Edinburgh Medical and Surgical

Journal, Volume 34

Toxicology

• Inadequate refrigeration• Decomposition of muscle• Histamine• Taurine• Cadaverine• Putrescine

• Histamine reaction• Heat stable

Symptoms

• Onset• 10min-2hours

• Flushing• Pruritis• Urticaria• N/V/D• Headache• Erythema

• Bronchospasm• Hypotension• Palpitations• Dysrhythmias• Death• 2014-2 Australians in Bali

Treatment

• No evidence for gastric decontamination• Supportive care• Antihistamines• H1 • H2

• Antiemetics• Bronchodilators

• Epinephrine?

Tetrodotoxin

• Incidence unknown• 100-300/yr in Japan

• Bacteria• Vibrio alginolyticus • Pseudoalteromonas tetraodonis

• Poison dart frog• Pacific newt• Blue ringed octopus• Trumpet and Ivory shell• Puffer fish

• Concentrated in liver, viscera, gonads, and skin

History

• Known by ancients• 2800 BC- 神农本草经 (The

Book of Herbs)• 2700 BC-Egyptian hieroglyphics• 1774-Captain Cook

• TTX• Heat stable• Sodium channel blockade• Rising phase of action potential

• Incredibly potent

Symptoms

• Onset• 10min-4hr

• Paresthesias of lips and tongue• Hypersalivation• N/V• Typically only lasts 8-12hr

• Hypotension• Dysrhythmias• Seizures• Coma• Death

Treatment

• Decontamination• Supportive care• Atropine• Volume• Pressors• Alpha agonists

• Anticholinesterases• Tensilon• Neostigmine

• Mortality improved ~60%(1886-1963) to ~20% (1995-2007)• Ventilators

Paralytic Shellfish Poisoning

• Incidence=?• 500 cases in California since

1927• 2009-136 exposures• Annual Report of the American

Association of Poison Control Centers' National Poison Data System

• Toxic algae bloom• Alexandrium tamarense complex

• Mussels, clam, oysters• 2002 Florida 13 cases from

pufferfish

• Warm months• Cold water

History

• 1689-Ephémérides des Curieux de la nature• 1801-Vancouver report• 1793 outbreak in British Columbia

Toxicology

• Saxitoxins• Saxitoxin• Neosaxitoxin• Gonyautoxins 1-4• Decarbamoylsaxitoxin

• Sodium channel blockade• Prevents impulse conduction

• Heat stable

Symptoms

• Onset• 30-60 min

• Paresthesias• Numbness: Face=>Limbs• Vertigo• Cranial nerve dysfunction• Normal reflexes and cognition

• Chest pain, tachycardia• Respiratory failure• Death• 1-12%

Treatment

• Decontamination• Supportive care

Amnesic Shellfish Poisoning

• Domoic acid poisoning • Algal bloom related• Nitzschia navis-varingica

• Gulf coast oyster, blue mussel, razor clams, butter clams• Dungeness crabs

• Anchovies

History

• 1987-Prince Edward Island• >100 people after eating mussels

• 1991-Santa Cruz• Large die-off of pelicans and cormorants

• 1991-Washington• 20 patients eating razor clams

• 1961-Santa Cruz and Capitola• Seabird attacks

Toxicology

• Domoic Acid• Neurotoxic amino acid

• Similar to glutamate• Hippocampus and amygdala

necrosis

Symptoms

• Onset• 1-24 hrs

• Starts with GI• N/V/D

• Neuro symptoms later• Up to 72 hours

• Seizures• Hemiparesis• Ophthalmoplegia• Memory loss• Coma• Death• 3%

Treatment

• Supportive Care• Benzodiazepines• Improve mortality in mice!

Questions?

• hensley@tamhsc.edu• ebmgonewild.com• x