MARINE TOXICOLOGY: ENVENOMATIONS & FOOD POISONINGS

1. MARINE TOXICOLOGY:ENVENOMATIONS &FOOD POISONINGS Sam L. Alexander, M.D.

2. Marine Envenomations • 2000 species of venomous marine animals • Initial, generalized treatment modalities: • Remove from water; avoid drowning • Local wound care • Specific antivenin (available?) • Manage anaphylaxis prn

3. Three Mechanisms of Envenomation

4. BITES • Octopi • Local wound care: • Irrigate • Debride • Dress • Tetanus • Analgesia • Blue-ringed Octopus (~lethal) • Tetrodotoxin-like venom

5. BITES • Sea snakes (Hydrophiidae) • 50 species, all toxic, 7 fatal • Most bites = No Envenomation: fangs short/loose ---> poor delivery of venom • Local wound care • Polyvalent Sea snake antivenin

6. NEMATOCYSTS • Nematocyst: spring-loaded venom glands, suddenly evert = delivering venom • Tentacles are common location • Functional after animal death • May still be ‘loaded’ while in victim flesh • Local Reaction • Allergic Reaction • Toxic Reaction (n/v/d, CP, cramps, SOB, paralysis, cardio-respiratory collapse)

7. WHAT IS A NEMATOCYST?

8. NEMATOCYSTS • General Medical Treatment • Cut off tentacles • Inactivate nematocysts: VINEGAR • Remove nematocysts: credit card scrape • Antihistamine • Analgesia • Antivenin exists only for sea wasp (box jelly fish)

9. NEMATOCYSTS • JELLYFISH • Local reaction (usually) • Remove tentacle~ • Vinegar • Credit card scrape • Antihistamine • Analgesia

10. NEMATOCYSTS • BOX JELLYFISH (Sea wasp) • Australia, Indian Ocean • Most deadly of all E.M.L. • 25% fatality rate; >sharks • One BOX can kill 10 humans • Cardio-respiratory arrest • Occurs within minutes • Medical Treatment: • ABC’s • Remove tentacles • Vinegar • Credit card scrape • ANTIVENIN! (Chironex)

11. NEMATOCYSTS • PORTUGUESE MAN-O-WAR • Southern US coast • Not a true jellyfish • Local reaction (usually) • Potential full CV collapse • Several reported deaths • Medical Treatment: • ABC’s • Remove tentacles • Vinegar • Credit card scrape • NO Antivenin exists

12. NEMATOCYSTS • Fire coral • Worldwide reef crests & shallow waters • Hawaii: conspicuously absent • Local reaction • Welts, redness, swelling, blisters, pus filled encystations • Possible N/V up to 3 hr post • Gone within 24 hr • Allergic reaction (uncommon) • Anaphylactic shock (rare) • Infection • Delayed Type IV hypersensitivity reaction

13. NEMATOCYSTS • Medical treatment • Irrigate copiously with HOT WATER; inactivates the proteinaceous toxin • Vinegar • Tetanus • Topical anesthetics • It may also ease suffering to repeatedly issue forth numerous expletives in a loud voice! • Antibiotics: if infected • Topical antihistamines: cortisone or Benedryl with poison ivy-like reaction

14. STINGS • Stinger: specialized apparatus that punctures skin = delivers venom • Medical Treatment: • Remove stinger(s) • r/o stinger in tissue with Xray • Irrigate copiously with HOT WATER • Hot as possible • 30-90 minutes; inactivates heat labile venom • Antivenin exists for Stonefish stings

15. STINGS • STARFISH • Most species non-venomous • Crown-of-thorns • Severe local reaction

16. STINGS • SEA URCHINS • Toxin coated spines • Severity depends on species • Local reaction (usually) • Problem: embedded spines

17. STINGS • STINGRAY • Barbs on tail • Shallow water hazard • Tail spines • laceration(s) • Stinger • Local reaction • =/- systemic reaction • (N/V/D, cramps, CP, SOB) • Medical Treatment: • stinger removal • Irrigate HOT water • Tetanus • Antibiotics (cover vibrio)

18. STINGS • BONY FISH (Lionfish, Stonefish) • Venomous spines on fins • Handled or stepped on • Will attack then swim away • Severe local reaction • Pain, swelling • Systemic reaction • N/V/D, syncope, SOB, paralysis, CV collapse • ANTIVENINexists for Stonefish

19. MARINE ENVENOMATION “TO KNOWS”

20. MARINE FOOD POISONING • Person who is sick after eating seafood…

21. MARINE FOOD POISONING • 44 y/o male ate seafood from a well-known, national seafood chain restaurant • Presents in E.D. 2 hr after eating variety/sampler of shrimp scampi, fried shrimp, red snapper and mahi mahi • C/O: N/V/D, cramps, perioral paresthesias, burning fingertips, ataxia, vertigo • Exam: Ice pack to forehead, skin hot to touch, watering eyes, diaphoretic

22. MARINE FOOD POISONING • Diagnosis? • Tetrodotoxin? Why or why not • How did you make the diagnosis? • Medical management?

23. MARINE FOOD POISONINGS • Food poisoning • Allergic reaction • Other diagnosis? • Other ddx of ? food poisonings presenting with neurological signs/symptoms: • MG, botulism, MSG, encephalitis, polio, organophosphates, anticholinergics, heavy metals, diptheria, Eaton-Lambert, plant ingestions, migraine, the bends!

24. FISH POISONINGS • Ciguatera • Scombroid • Tetrodotoxin

25. CIGUATERA • Most common vertebrate fish poisoning • World wide, warm water, 90% occurs in spring/summer months • >500 species of fish but ALL ARE LARGE • Red snapper, seabass, baracuda, grouper, kingfish, sturgeon, parrot fish

26. CIGUATERA • Ciguatoxin • Algae/protozoa…….small fish…….large fish • Heat stable; cooking does NOT kill • Binds Na+ channels & increases permeability • Variable toxins thus variable symptoms • Ciguatoxin can be assayed (? can our lab) • Toxin is absorbed quickly thus ONSET of symptoms is 1 -6 hrs after eating

27. CIGUATERA

28. CIGUATERA • Management • ABC’s (include fluid resuscitation) • Activated charcoal (<2hr) • Cathartics (if no diarrhea) • Mannitol • 1 g/kg over 30 min; decreases neurological effects of the ciguatera toxin

29. SCOMBROID • Any large fish (Mahi mahi, amberjack) • Preventable • Proper food handling • Spoiled fish may have honeycombing appearance • Peppery taste • Bacteria converts histidine to the toxins saurine and histamine • Onset signs/symptoms within minutes-hours

30. SCOMBROID • Presents similar to allergic reaction • Diffuse erythema (face, neck, torso) • may progress to urticaria • Numbness, tingling, perioral burning • Bronchospasm • Diagnosis • Increased serum or urine histamine levels • Test fish • NOT a fish allergy if • Others having same symptoms • Fish can be tested

31. SCOMBROID • ? Alternate diagnosis of s/s • Anaphylaxis, anaphylactoid reaction, ethanol flush, tartrazine, metabisulfites, tyramine, scombroid, MSG • Management • Benadryl, ranitidine • Ventolin prn • ? Activated charcoal (if early) • ? Cathartic • Epinephrine (if needed)

32. TETRODOTOXIN • Primary sites: • Japan • California • Africa • Australia • > 100 fish species • Puffer fish (FUGU) • Blow fish • Toad fish • Balloon fish • Globe fish • ALSO • Crab eggs • Blue-ringed octopus • Newts

33. TETRODOTOXIN • Tetrodotoxin • Heat stable • Concentrated in ovary, liver, skin, intestine • Be afraid of female fishy in heat! • Can be assayed • Blocks Na/K+ activity • Blocks neuromuscular activity • Onset within MINUTES of ingestion

34. TETRODOTOXIN • E.D. presentation • H/A • Paresthesias (lips, tongue, mouth, fingers/toes) • Dysphagia, dysarthria, ataxia, fasiculations • Ascending paralysis • Respiratory arrest • Management • ABC’s • AC and cathartics • 50% MORTALITY rate

35. SHELLFISH POISONING • General information • Mollusks filter dinoflagellates and algae • Most common during red tides (dinoflagellates go crazy) • Any shellfish ingestion • Clam • Oyster • Muscle scallops • Three types • Paralytic (PSP) • Neurotoxic (NSP) • Amnesic (ASP)

36. PARALYTIC SHELLFISH POISONING (PSP) • Onset <30 minutes • Saxitoxin blocks Na+ voltage gated channel • Neuro symptoms predominately • Paresthesias, ataxia, vertigo, weakness, paralysis, cranial neuropathies, respiratory failure • N/V/D/cramps LESS common, not unlikely • Management • Supportive • Possible lavage and cathartics

37. NEUROTOXIC SHELLFISH POISONING (NSP) • Onset 15 min-18 hr; average 3 hours • Brevitoxin • GI + Neuro symptoms • N/V/D/cramps • Paresthesias, temp reversal, ataxia, vertigo, areflexia, NO paralysis • Management • Supportive • Ventolin • (?) decontamination

38. AMNESTIC SHELLFISH POISONING (ASP) • Onset 15 min-36 hr; average 5 hours • Domoic acid (Canada 1987) • GI + Neuro + CV symptoms • N/V/D/cramps • MEMORY LOSS (damage to amygdala and hippocampus) Seizures, grimacing, chewing • Opthalmoplegia less common • Hypotension & arrhythmias • Management • Supportive • (?) decontamination

39. OTHER POISONINGS • Botulism • Canned foods classic, can be from fresh fish • GI = neuro • Diplopia, dysphagia, dysarthria, weakness • Toxin binds at NMJ • Alternate diagnosis considerations • Myasenia gravis, eaton-lambert, tick paralysis, gullian barre’, miller-fisher syndrome

40. SUMMARY of FISH POISONING

41. SUMMARY of SHELLFISH POISONING

42. QUESTIONS???