Big Bend Florida
Fish Poisoning - The name may be difficult to
remember. But if you get this disease, you'll never forget it.
by Donna G. Blythe, M.D., Donald P. de
and Susanne Cramer-Castro, B.A.
poisoning is endemic wherever coral reef fishes are a food source. In
South Florida, this includes the local coral reef fishing grounds as
well as all of the
It is the most frequently reported seafood-related disease.
results from the eating of reef fish affected with ciguatoxin.
Ciguatoxin originates from a dinoflagellate name Gambierdiscus
toxicus which colonizes coral beds. The toxin first affects the
coral-grazing fish and is then passed up and through the food chain to
the piscivorous fish (i.e., snapper, grouper, amberjack, barracuda)
and finally to man. The toxin is not affected by either cooking or
freezing, and the affected fish, cooked or raw, is not tainted by
bacteria in any way. Typically, the victim states, "It was the best
fish I ever tasted."
symptoms were first described in the 1500's by the Spanish explorers
to Cuba and were attributed to the ingestion of a small snail which
they called cigua.
In the Pacific,
the first Tahitian death on the ship Bounty (of the famous Mutiny
on the Bounty) was the ship's surgeon after a fish feast: "Old
Bacchus died not of drink, as might have been supposed, but of eating
a poisonous fish."2
Today a typical
scenario would include a delicious family fish dinner at the evening
meal, perhaps applauding the successful fisherperson and the culinary
skills of the cook. Several hours later (and always in the wee hours
of the morning) the rather sudden onset of gastrointestinal complaints
awakens one after another of the fish-feasters. Nausea, vomiting,
cramping, abdominal pain, and diarrhea suggest that perhaps the fish
itching, joint and muscle pain, tingling of the lips, burning or pain
when cold liquids are touched or drank will usually bring at least the
more affected victims to the emergency room, later to find most if not
all the others who also enjoyed the fish were variably affected. With
the exception of ice applied to the tongue or fingertips being
interpreted as a burning sensation, there are no clinical signs.
There is no
diagnostic laboratory test. Diagnosis rests with the history of
ingestion of reef fish followed by gastointestinal and bizarre
neurological complaints all within a few hours' time frame. The
coup de grace in diagnosis is the observance that the symptoms and
intensified after the consumption of an alcoholic beverage.
As an aside,
breast-feeding infants have been reported to exhibit an unusual degree
of "fussiness" if their mothers have been victims of ciguatera and it
is believed that the ciguatoxin is excreted in breast milk.
traditionally been supportive and disappointing. This has included
antihistamines, amitriptyline, calcium gluconate, pyridoxine,
corticosteroids, atropine and vitamin B. Recently ciguatera has been
successfully treated with IV mannitol.4 The usual dose is 1
gram of mannitol per kilogram victim's body weight infused
intravenously either as a 20 percent mannitol solution or added to .9
NaCl or Ringer's solution.
For help with
this treatment, call the Ciguatera Hotline at (305) 361-4619 or
on the sodium channels, thereby causing changes in the electrical
potential and permeability of cells. It is believed that mannitol
might compete at the cell membrane and/or render the ciguatoxin inert.
A scavenger effect is also possible and mannitol might also increase
elimination of th toxin via its secondary diuretic effect.
Some of the
symptoms can recur hours after treatment, suggesting further
ciguatoxin absorption from the gastrointestinal tract; retreatment has
been successful in these cases.
ciguatera is usually a self-limited disease lasting one to two months.
However, symptoms can persist months to years, causing great anguish.
1 gm/kg Body Weight
Mannitol Injection, USP, 25%
12.5 grams/50 cc vial
Standard Man = 75 kg
75 gr = 6 * 12.5 mg vial
= 6 * 50 cc = 200 cc
Additive: 700 cc D5W or .9 NaCl
Infusion Rate: 250 - 350 cc/hr
Total Infusion Time: 3-4 hrs
believed to abbreviate if not abate the clinical sequelae of ciguatera
fish poisoning. Preliminary evidence suggests that the earlier a
victim is diagnosed and treated, the more likely the success with IV
experience of the first author, mannitol has been shown to be safe and
effective in patients aged 4 to 72 years old, even when given to an
8-month-old breast-feeding infant was apparently successfully treated
recently in the Marshall Islands, where the use of IV mannitol in
ciguatera was pioneered and now is the site of a NIH double-blind
study on the use of IV mannitol in ciguatera fish toxicity.
there is no commercial assay available to test potentially toxic fish.
A rapid enzyme immuno-assay for the detection of ciguatoxin in
contaminated fish is currently being evaluated.5 To be
marketable the test would have to be effective, inexpensive, and
simple to use. Until this is available, avoidance of potentially toxic
fish makes sense. This includes large predatory reef fish (greater
than 5 pound snapper to 5 pound grouper or amberjack or greater than 2
pound hogfish seems a realistic guideline). Yellowtail snapper and
dolphin (mahi-mahi) are safe fish to eat at any size in the South
Florida and Caribbean areas.
know what kind of fish you are eating. Unsuspecting tourists have been
known to have been sold barracuda thinking they are buying red snapper
from an artful seaside fish peddler. A restaurant can "switch" a large
grouper fillet for a yellowtail snapper, and most fish fanciers
wouldn't know the difference. Make sure the fish is served whole (OK,
headless) whenever possible. A fish small enough to fit on your plate
is probably safe.
Percentage of symptoms reported by ciguatera victims.
(not on ciguafile)
from ciguatera victims
Symptoms worsened with alcohol, sweets, nuts, or coffee
Double Vision/Eye Irritation
Pain - Penis/Scrotum
Pain with Intercourse
1) JAMA. Laurence et al, 1980, 244:254-258
2) "Mutiny on the Bounty," Nordoff and Hall, 1932, pg. 94
3) JAMA, Bylthe and de Sylva, Oct. 24/31, 1990
4) JAMA, Palafox et al, May 13, 1988
5) Hokama, Toxicon, 1983:21-817