Marine Poisoning and Envenomation

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Marine Poisoning and Envenomation

• Jennifer Hughes
• Dr. David Johnson
• February 16, 2006

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Le grand plan

• Marine envenomation
• Toxic animals that live in the ocean
• Mechanisms of envenomation
• Learn a little about venom
• Treatment
• Marine poisoning
• Foods and food preparation to avoid
• Recognize the dangerous causes
• Learn a little about the toxins
• Prepare for your next beach holiday
• Not covering botulism, food poisoning

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Poisoning vs Envenomation

• Marine envenomation
• glands that produce venom
• applied or injected parenterally
• painful
• CV effects
• Marine poisoning
• animals accumulate toxins from environment
• do not produce them
• must ingest for toxic effect
• GI and neuro clinical effects

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Venom and Anti-venom

• mosaic of antigens
• Circulating and tissue-fixed
• Can be deeper than typical snake bites
• Circulating venom neutralized by specific
  immunoglobulins (anti-venom)
• Anti-venom rarely reverses pathology at site of
  envenomation

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Marine Envenomations

• Worldwide 40,000-50,000 envenomations each year
• Significant risk for swimmers in open-water
  athletic events
• Typically divide into vertebrates and
  invertebrates

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• Stingray wounds are often complicated by
  infections with
• Staph aureus
• Streptococcus
• Vibrio vulnificans
• Pasteurella multocida
• Pain relief in Stonefish stings can be provided
  by
• Peeing on the wound
• Vinegar
• Immersion in hot water
• Scraping the wound with a credit card

• Anti-venoms exist for
• Sea snakes
• Sting rays
• Stonefish
• A and C
• A and B

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Vertebrates

• Stingrays
• Scorpaenidae (Stonefish, lionfish, scorpionfish,
  tigerfish, zebrafish, turkeyfish)
• Sea snakes

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Stingrays

• 11 species in US coastal waters
• Burrow in shallow sand
• Tail barb reflexively fires
• Most common injury secondary bacterial infx
• Venom phophodiesterase, serotonin
• HEAT LABILE

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Stingrays

• Symptoms
• Severe pain and burning locally
• Intensifies for several hours
• Systemic effects muscle cramping, weakness,
  tremor, syncope, cv collapse, seizures
• Fatality rare (chest injuries, bleeding, tetanus)
• Mx
• Clean and debride wound, td proph, tx of
  infection
• Vibrio vulnificus (Ancef)
• Pain control by immersing in hot water (45 C)

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Scorpaenidae (stonefish/lionfish)

• Scorpaenidae most common vertebrate to sting
  humans
• Gulf of Mexico, Pacific and Indian Ocean

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Stonefish

• Can be fatal!!
• Will attack humans if threatened
• Venom glands at tip of spines
• Verrucatoxin, nor-epi, dopamine, tryptaphan
• Stonustoxin (activates nitric oxide pathway)

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Stonefish

• Clinical signs and symptoms
• Excrutiating pain (LOC)
• Induration, ecchymosis, hyperesthesia, dyesthesia
  or anesthesia of affected limb
• N/V, diaphoresis, dyspnea, hypotension, syncope
• Cardiac dysrhythmias, conduction abn, ischemia,
  pulmonary edema, sz, paralysis

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Lionfish

• Dont normally attack
• Smaller venom glands
• Venom PGE2, Thromboxane B2, PGF2
• Severe burning and swelling
• Rare CV or neuro effects

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Treatment of All Scorpaenidae

• Soak limb in hot water
• Oral analgesic, local block
• Remove barbs/spines
• Excise blisters (full of venom)
• Tetanus
• Antibiotics
• ANTI-VENOM (usually used for stonefish)

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Sea Snakes

• 50 species
• Pacific and Indian Ocean
• NONE in Atlantic or Caribbean
• All are toxic, seven species fatal to humans
• Most bites harmless ? fangs too short!

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Sea Snakes

• Venom
• Peripheral neurotoxin
• Alters Na, Cl- permeability without changing
  Na-K-ATPase pump
• Symptoms occur with no local rxn
• 3-6 hrs cranial and peripheral neuropathies
• Paralysis, resp failure, myonecrosis,
  myoglobinuria, renal failure

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Management of Sea Snake bites

• Stabilize vitals
• Polyvalent sea snake anti-venom

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Invertebrates

• Jellyfish (box jellyfish, Portuguese man-of-war)
• Sponges
• Cone shells
• Octopi
• Sea anenomes
• Coral
• Sea urchins

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Quiz

• A group of jellyfish traveling together is called
  a
• School
• Smuck
• Fleet
• Gaggle

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Jellyfish

• Venom bradykinin, serotonin, histamine, PGs,
  adenosine, phosphodiesterase, fibrinolysin,
  hemolysin
• All have long tentacles hanging from
  pneumatophore
• Venom injected by nematocysts
• Most result in local reaction, stinging,
  ulceration, anaphylactoid rxn

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What is a Nematocyst?

• Nematocyst spring - loaded venom gland that
  suddenly everts and delivers venom
• Located on tentacles, spicules, etc
• Continue to fire after animals death
• May still be loaded when in skin
• Local reaction, allergic reaction, toxic reaction
  (N/V/D, CP, cramps, SOB, paralysis,
  cardiorespiratory collapse)

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Portugese Man-of-War

• Florida
• July-Sept after tropical storm
• Excrutiating pain, welts, myalgias, HA, resp
  distress, CV collapse
• multiple stings ? death
• Mx ABCs, remove tentacles, vinegar, credit card
  scrape, NO antivenom exists

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Box jellyfish (sea wasp)

• Most deadly of all stinging marine life
• Australia, Southeast Asia
• Enough venom to kill 10 adults
• Fatality rate of 20
• Hypotension, muscle spasm, resp paralysis,
  cardiac arrest
• Death can occur within 30 sec

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Mx of Jellyfish envenomations

• INACTIVATE nematocysts (convince someone to pee
  on you, vinegar)
• REMOVE tentacles and nematocysts by shaving or
  scraping credit card
• Dont use fresh water
• Td
• Antibiotic prophylaxis prn
• ANTI-VENOM for box jellyfish (Chironex)

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Other invertebrates

• Fire coral
• nematocysts, local rxn
• Sponges
• inject venom with spicules ? local rxn
• Cone shells
• snails inject venom through long tooth
• typically local rxn but can get CV collapse
• Blue-ringed octopus
• bites rare ? tetrodotoxin
• mx supportive
• Sea urchin
• venom gland on spicule
• local rxn, embedded spine can be problematic

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To sum it all up

• Really bad (/- fatal)
• Stonefish (ANTIVENOM)
• Sea snakes (ANTIVENOM)
• Box jellyfish (ANTIVENOM)
• Man-of-war jellyfish (with multiple stings)
• Blue-ringed octopus
• Not quite as bad
• Stingray
• Many sea snakes
• Lionfish
• Corals, sponges, sea urchins, cone shells

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To sum it all up
Thanks Rob!
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Quiz

• What is the definition of ichthyosarcotoxic?
• Toxins causing pruritis as main symptom
• Fish-borne toxins that specifically target muscle
  of victim
• Toxins from muscle, viscera and gonads of fish

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Marine Poisonings

• Affect voltage gated Na channels
• Myelinated and unmyelinated nerves
• Typically peripheral neuropathies
• Can get flaccid paralysis

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Mr and Mrs Scuba

• A young healthy couple on their honeymoon in
  Nicauragua had a local dinner of rice, beans, a
  large red snapper, canned fruit and wine.
• Five hours after dinner, both developed abdo
  pain, diarrhea, vomiting, then headache, numbness
  in arms and legs, and bone and tooth pain. When
  the woman reached for a hot washcloth to rub on
  her freezing skin, the washcloth felt cold.
  This sensation lasted for 3 days. Within 4 days,
  their symptoms completely resolved.

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Approach

• What did they eat?
• Where was it caught?
• If not eating, other activities?
• Pattern of neurological symptoms?
• Onset of symptoms?
• Can you make the diagnosis?
• Management?

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Ciguatera Poisoning

• Most common fishborne poisoning
• Endemic to warm-water, bottom-dwelling shore reef
  fish
• 35 degrees north 35 degrees south
• MAY-AUGUST
• 500 fish species involved barracuda, sea bass,
  parrot fish, red snapper, grouper, sturgeon

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Ciguatera

• Dinoflagellates (plankton protozoa) contain
  ciguatoxin
• Small fish eat dinoflagellates
• Bigger fish eat small fish
• Really big fish (gt5 lbs) eat bigger fish
• People eat really big fish
• Ciguatoxin increasingly concentrated in flesh,
  fat and viscera of larger fish

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Ciguatoxin

• Lipid soluble
• Acid stable
• Heat stable
• Odorless/tasteless
• Fresh and frozen fish
• Prolonged opening of voltage gated sodium
  channels in nerves and muscle tissues

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Ciguatoxin signs and symptoms

• 2-6 hours after ingestion
• 75 within 12 hours
• 96 within 24 hours
• Clinical diagnosis

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• Gastrointestinal
• N/V/D
• Neurological
• Paresthesias, dysesthesias
• Sensation of loose, painful teeth
• Cold allodynia (pathognomic)
• Ataxia
• Vertigo, seizures, visual disturbances
• Cardiovascular
• Bradycardia
• Hypotension
• Diffuse Pain Syndromes
• Headache
• Myalgias
• Arthralgias

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Natural History of Disease

• Mortality
• 0.5
• Usually patients with comorbidities
• Duration of symptoms
• GI
• 24-48 hours
• Bradycardia Neuropathy
• Days to weeks

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Management

• Inducing vomiting likely unhelpful
• Supportive
• Activated charcoal (acc to Goldfrank)
• Cathartics
• IV Mannitol

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Mannitol

• Though to decrease neuro and muscular symptoms
• Evidence from
• Single cases
• case series
• Uncontrolled trials
• Non-randomized trials
• Animal studies

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• RCT N50
• Inclusion
• Consumed local reef fish
• Neurological and GI symptoms within 48 hours
• Treatment
• Mannitol 20 - 500ml bolus
• NS 500ml bolus

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Primary Outcomes

• Evolution of 13 items (5 point Likert scale) over
  24 hours
• Unvalidated scaleItems
• GI symptoms
• N/V, diarrhea, cramping
• Neurological symptoms
• Numbness, dysesthesia, cold allodynia
• Diffuse pain symdromes
• myalgias, arthralgias, HA
• Other
• Pruritus, dizziness, general weakness, dysuria

• Evolution of neurologic status at baseline and 24
  hours

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Secondary Outcomes

• Need for additional medication
• - acetaminophen, scopolamine, butylbromide,
  promethazine, NS, atropine
• Frequency of poor responders
• Hospitalization gt24 hours
• Administration of open label mannitol
• Rehospitalization
• Subjective treatment satisfaction

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Results

• Improvement of symptoms
• Mannitol - 96
• NS - 92
• p-value 1.0
• Asymptomatic patients at 24 hours
• Mannitol -12
• NS 24
• p-value 0.46
• Asymptomatic patients at 1 week follow up (70)
• Mannitol 28
• NS 28
• Discomfort caused by treatment
• Mannitol - 84
• NS 36
• p-value 0.0015

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Conclusions

• Mannitol equivalent to NS in relieving SSx of
  ciguatera poisoning
• Mannitol has more side effects
• NS unlikely to have treatment effect, so dont
  use either

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Treatment of Chronic Neurological Effects of
Ciguatera Poisoning

• Multiple case reports
• Gabapentin
• Amitryptilline
• Nifedipine
• Fluoxetine
• Tocainide
• No real evidence

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Mr. Flush

• 54 yo M back from a week-long sport fishing trip
  in Hawaii. He brought some fish back with him
  (didnt declare it to customs) and cooked some up
  tonight for dinner washed down with several
  glasses of Chilean wine.
• 15 minutes after eating, he developed burning in
  his mouth, generalized pruritis, dysphagia,
  headache, followed by vomiting and diarrhea. On
  exam in the emergency department, his BP was
  normal and his face and torso were bright red.

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Approach

• What did they eat?
• Where was it caught?
• If not eating, other activities?
• Pattern of neurological symptoms?
• Onset of symptoms?
• Can you make the diagnosis?
• Management?

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Differential

• Anaphylaxis/anaphylactoid reaction
• Tyramine (wine, cheese)
• MSG
• Metabisulfites (wine, fruit, shrimp preserv)
• Tartrazine (yellow colouring food additive)

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Scromboid poisoning

• Eating cooked, smoked, canned or raw fish
• Mahi mahi and amber jack most common (CDC)
• PREVENTABLE

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Remember scromboid histamine

• Histidine found in dark meat
• Morganella morganii, E.Coli, Klebsiella
  pneumoniae contain histidine decarboxylase enzyme
• Converts histidine to histamine and saurine in
  WARM fish
• Healthy fish lt 0.1 mg/100 g of fish
• 12 hours at room temp 100mg/100g of fish
• Toxic 50 mg/100g
• Normal appearance, taste and smell
• Rarely honeycombing and peppery taste

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What Scromboid looks like

• Symptoms begin in minutes to hours
• Numbness, tingling, burning of mouth
• Dysphagia
• Flush (face, neck, torso)
• GI symptoms
• Rare pruritis, angioedema, bronchospasm

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Management

• Activated charcoal
• Supportive (fluids)
• Antihistamines
• H2 receptor antagonist
• B2 adrenergics/epi
• Excellent prognosis
• Blasely ML. Scombroid poisoning prompt
  resolution of symptoms with cimetidine. Ann Emerg
  Med 1983, 12 104-106.

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Ms. Oy

• A 23 yo female eats out at an local oyster bar in
  Charlottetown in celebration of finishing
  university for the summer.
• Later that evening she starts vomiting. 2 days
  later her friends notice that she is not
  remembering simple things in their conversation.

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Approach

• What did they eat?
• Where was it caught?
• If not eating, other activities?
• Pattern of neurological symptoms?
• Onset of symptoms?
• Can you make the diagnosis?
• Management?

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Shellfish poisoning

• Mollusks eat dinoflagellates May-August
• Oysters, clams, mussels, scallops
• 3 categories
• Paralytic shellfish poisoning (PSP)
• Neurotoxic shellfish poisoning (NSP)
• Amnestic shellfish poisoning (ASP)

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Paralytic Shellfish Poisoning (PSP)

• Onset 1 hour
• Saxitoxin blocks voltage gated sodium channels
• Dose-related toxin
• Fatality from resp failure
• Mortality 6
• Mx lavage, supportive, intubation

• Numbness
• Sensation of floating
• Ataxia
• Muscle weakness
• Cranial nerve dysfunction
• Paralysis

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Neurotoxic Shellfish Poisoning (NSP)

• Onset mean 3 hours
• Brevetoxin (P.brevis)
• Just like ciguatera poisoning but NO
  PARALYSIS
• Not fatal
• Mx supportive, ? Ventolin (Goldfrank)

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Amnestic Shellfish Poisoning (ASP)

• Onset mean 5 hours
• Domoic acid
• Only documented outbreak Canada 1987 from mussels
  in PEI
• Mortality 2
• 10 longterm memory loss, neuropathy
• Mx decontamination, supportive

• Symptoms
• GI N/V/D/cramps
• Neuro MEMORY LOSS (damage to amygdala and
  hippocampus)
• sz, grimacing, chewing, opthalmoplegia less
  common
• CV hypotension and arrythmias

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Miss Fugu

• A 23 yo F is teaching English in Japan. She
  presents to the hospital complaining of sudden
  onset of headache, numbness in her lips, tongue,
  face and feet after eating Fugu, a local
  delicacy.
• When you check on her in 5 minutes, her mouth has
  developed bullae, she is drooling, cannot walk
  any longer, and is now in severe respiratory
  distress.

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Killer Fugu!

• Tetrodotoxin Poisoning
• Mortality 50 in some studies
• Only Tetraodontiformes Order
• Japan, California, Africa, SA, Australia
• 100 speciesglobefish, balloonfish, blowfish,
  toadfish, blueringed octupus.
• 2 newts in Oregon, California and Alaska can be
  fatal
• Sims et al. Pufferfish poisoning emergency
  diagnosis and management of mild human
  tetrodotoxication. Ann Emerg Med 1986, 15
  1094-1098

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Tetrodotoxin

• Found in liver, ovary, intestines, skin
• Heat stable
• Water soluble
• Dose-dependent
• Inhibits Na-K pump and blockade of neuromuscular
  transmission

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Tetrodotoxication

• Onset within minutes
• Neuro HA, diaphoresis, dysesthesias,
  paresthesias (lips, tongue, face, fingers, toes),
  dysphagia, weakness, ascending paralysis in 2-4
  hours
• Skin Buccal bullae, salivation
• GI N/V/abdo pain
• CV hypotension

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Clinical grading for tetrodotoxin
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Diagnosis

• Clinical
• Tetrodotoxin detected in urine up to 5 days
  post-ingestion
• 24 hour urine collection

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Management

• Decontamination (charcoal, GL, cathartic?)
• Airway protection
• Supportive

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Summary of shellfish ingestion
Thanks Rob!
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In summary
Thanks Rob!
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References

• Isbister et al. Neurotoxic marine poisoning.
  Lancet Neurology 2005 2 219-28.
• Schnorf, et al. Ciguatera fish poisoning a
  double blind, randomized trial of mannitol
  therapy. Neurology 2002 58873-880.
• Sims et al. Pufferfish poisoning emergency
  diagnosis and management of mild human
  tetrodotoxication. Ann Emerg Med 1986, 15
  1094-1098
• Tunik, M and L. Goldfrank. Food poisoning. In
  Goldfranks toxicologic emergencies, seventh
  edition. 2002 pp.1085-1099.
• Weisman R. Marine envenomations. In Goldfranks
  toxicologic emergencies, seventh edition. 2002
  pp.1592-1598.