MARINE TOXICOLOGY: ENVENOMATIONS

1
MARINE TOXICOLOGYENVENOMATIONS 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
  ---gt 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 gtsharks
• One BOX can kill 10 humans
• Cardio-respiratory arrest
• Occurs within minutes
• Medical Treatment
• ABCs
• 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
• ABCs
• 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
• ANTIVENIN exists 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
• gt500 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
• ABCs (include fluid resuscitation)
• Activated charcoal (lt2hr)
• 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
• gt 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
• ABCs
• 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 lt30 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???