Sushi Parasites & Fish Sushi Parasites & Fish PoisoningPoisoning

Part 1Part 1Killer SashimiKiller Sashimi

The Good

The Bad

Jejunum resected for acute abdomen one day after eating sashimi

Anisakiasis

Anisikid Nematodes

Anisakis simplex (herring worm), and related worms Pseudoterranova spp. Contraceacum spp.Most cases in Japan3 cases reported in San Francisco after eating sushi (1988)By 1988, about 50 cases in US had been reportedNew England Journal of Medicine (319:1128-29, 1988

Gastric and Intestinal Anisakiasis

Larva in cross-section, burrowed into intestinal wallPatient may feel tickling in throat & cough up worm Anisakiasis most commonly affects stomach

Related HelminthNecator Americanus

Hookworm

Bloodsucker

Huge cause of anemia, decreased economic productivity, infertility.

Cost South Civil War?

Anisakiasis

Larvae of A.simplex

Final hosts are dolphins & whales

1st intermediate host is krill

2nd host is fish/squid 150 spp.

Acute gastric disease, occurs 1 to 2 h after eating raw fishEndoscopic removal is treatment of choiceOccurs in sensitized individuals

Intestinal Anisakiasis

Presents as Acute Abdomen

Confused with appendicitis, Chron’s, Gastrointestinal Cancer.

Diagnosis made after surgery

Extragastrointestinal involvement is possible

Omentum, liver, abdominal wall

My oh Moi!

Risky Fishes

Larvae occur frequently in:

cod, haddock, fluke, pacific salmon, herring, flounder, and monkfish Illuminating filets of fish (candling) mostly ineffective

Bilateral Hydro-pneumothorax

21 yo M ate pickled crabs 3 weeks priorPleuritic chest pain and pink sputumParagonimiasisWorm inflammatory response allows eggs to migrate into bronchus & sputum

Pulmonary manifestations of Paragonimus westermani

Ingested Paragoniumus metacercaria migrate to pleural cavity Cause pneumothorax, pleural effusionsCommon cause hemoptysis in SE Asia

TB or Parasite?Cystic findings in lung

TB common in these locales. Misdiagnosis in 50%

Loffler syndrome - eosinophilic infiltrates migrate side to side

Soap bubble sign

Pt ate raw Japanese mitten crab

Paragonimuswestermani

Calcified “bubbly” frontal lobe lesion

Cerebral Paragonimus Disease

Encapsulated cerebral ovaIn Japan, river crabs are placed next to raw fish 2cm long, they carry P. miyazakiiShould not be eaten even if cooked!

Albuquerque Sushi Case

40 yo male presents to ED at Albuquerque VA

He has passed a pale 1 meter long parasite

No symptoms

Only exposure to fish, he states, is homemade sushi made from salmon

Diphyllobothrium latum

Full grown worm from 1 to 15 meters!Longest human tapewormPatient may vomit or pass worm2% symptomatic anemiaworm has affinity for vitamin B12

Freshwater & Andromous Fish

AKA Scandinavian or Jewish Housewife’s diseaseHomemade Gefiltefish or Fish BallsAbsent Great Lakes1980 outbreak involved 4 physicians in LA, who ate salmon sushi (CDC)

Diphyllobothrium latumDiagnosis: worm, operculate eggs in stool.Adult may produce 1 million eggs per day.Treat with Praziquantel or Niclosamide Available from CDC

D. latum Proglottid contain gravid uterus and several eggs.

Prevented by avoiding raw or pickled fish

Superficial larva migrans

38 yo M who developed abdominal rash after eating firefly squid!

More commonly larva migrans appears after going barefoot in tropics

Br J Derm Aug 1998 (139) 2: 315 

Nematode larva Spirurina

FDA recommendations

All fish and shellfish intended for raw (or semiraw such as marinated or partly cooked) consumption be:1) Blast frozen to -35°C (-31°F) or below for 15 hours, 2) Or, regularly frozen to -20°C (-4°F) or below for 7 days.

Part 2Now we’re cookin’

Grilled Walu (Yum!)

Ichthyosarcotoxism

AKA poisoning by fish fleshExcludes shellfish poisoningExcludes bacterially contaminated fishOften misdiagnosed as gastroenteritisA wide variety of fish are implicated

Ciguatera Most prevalent Ichthyosarcotoxism

Over 400 fish species are implicated

Mainly large, carnivorous fish

Grouper, Snapper, Barracuda, Surgeon Fish, and Moray Eel.

CDC case report

17 crew members of cargo ship fell ill in Freeport TX, in 1997 with nausea, weakness, and paresthesias

All had eaten barracuda - later found to be ciguatoxin positive

All recovered

120 cases reported to CDC in decade prior in US

Crew Member’s Symptoms

Diarrhea (100%) Abdominal Cramps (82%) Nausea/Vomiting (76%)Muscle Weakness (88%) Itching/Numbness of mouth (65%) Temperature reversal (65%) Acroparesthesias (65%) Dizziness (59%)

Ciguatera Clinical FeaturesDelayed Onset: 4-10 hours post ingestion

Initially: GI, nausea, vomiting, and diarrhea

Later: Neuro, paresthesias, temperature reversal – Hot objects feel cold on skin or in mouth

Heart block may occur

Ciguatera pathogenesis

Ciguatoxin is produced by dinoflagellate protozoan – Gambierdiscus toxicusReef fish can concentrate the toxin in fleshToxins are stable, resistant to cooking.Ciguatoxin alters membrane properties of cellsActivates voltage dependent sodium channels in nerve and muscle

Ciguatera Treatment

Activated Charcoal

Supportive care

Correction of dehydration

Mannitol and Calcium have been reported to have benefits anecdotally

Neurologic symptoms may last months

Mortality is low < 1:1000

Ciguatera case report

Two Marshallese men (30 and 31 y.o.) developed circumoral numbness and tingling in fingers two hours after eating fresh-caught cooked snapper3 hours: burning sensation on drinking or touching water; marked weakness, then joint pains & lethargy. 6 hours: unconscious, responded only to pain, with flaccid paralysis.

JAMA, May 13, 1988 - Vol 259, No. 18

JAMA, May 13, 1988 - Vol 259, No. 18

72 hours: LR was given at a rate of 125 mL/h250 mL of 20% Mannitol solution administered IV at a rate of 500 mL/h while they were evacuated by aircraft. One patient stood up ten minutes after mannitol therapy was started; the other patient, confused, sat up after five minutes. Both discharged, fully recovered 48 hours after treatment.

Randomized Trial Mannitol50 patients: after 24 hours, 96% mannitol-treated patients vs. 92% saline-treated patients had improved (p = 1.0)12% and 24% of patients in each group were asymptomatic (p = 0.46). Infusion pain: mannitol group (84%) > NS group (36%) (p = 0.0015). Mannitol was not superior to NS in relieving symptoms and signs of CP but had more side effects. Ciguatera fish poisoning: a double-blind randomized trial of mannitol therapy. Schnorf H - Neurology - 26-MAR-2002; 58(6): 873-80

Ciguatera Prevention

Avoid eating the biggest specimens of reef fish

Avoid eating scaleless fish (eels)

Avoid viscera – makes sense to me!

Probably this one’s ok

FuguToxic Pufferfish

Known in sushi bars as Fugu

Fugu is prepared by specially trained chefs in Japan.

Several tens of cases each year in Japan

Mortality exceeds 50%!

Fugu/Tetrodotoxin poisoning

Most powerful emetic known

Causes severe GI upset with profound vomiting, pain.

GI symptoms are often accompanied by paresthesias, ataxia, respiratory depression.

Victims proceed to coma, convulsions, and death within hours

Tetrodotoxin

Axonal blocking agent, interferes with cytochrome system

Often causes bradycardia, heart block, circulatory failure, seizures, hypothermia.

Treatment is supportive, ICU, pressors, fluids, AC charcoal probably doesn’t hurt.

Internal Medicine Applicant Dinner at Season’s Restaurant

3 IM attendings ate tuna

1 applicant from Florida ate steak

Dr. Magrep developed diarrhea, flushing and subjective fever, mild pruritis.

Comparing notes the next am, 2 colleagues reported same symptoms

Applicant survived process.

ScromboidScromboidae Family - Tuna Mackerel

Dark fleshed migratory species of pelagic fish.

Mackerel, tuna, bonito, mahi-mahi

Humans ingest canned tuna, smoked mackerel, tinned sardines - most cases

Also “ripe” fresh fish

Scromboid

Rapid onset of symptoms – within 10 minutes

Maximal symptoms within 2 hours

Like others, causes acute GI distress – vomiting, cramps, diarrhea.

Skin: erythema, urticarial patches, edema, facial swelling

Often confused with allergic reaction

Very seldom fatal

Pathogenesis

Histidine in fish flesh.Histidine is converted to histamine in gutWidespread activation of mast cellsTreatment antihistamines!H2 blocker provides superior relief than H1 blocker, but no reason to not give bothIV cimetidine produces rapid resolution of sx

Questions?