Environmental Engineering Reference
In-Depth Information
fish cannot be detoxified by cooking them. Symptoms include
gastrointestinal effects such as nausea, vomiting, and diarrhea,
and neurological symptoms such as headaches, muscle aches,
numbness, vertigo, and hallucinations. Severe cases can also
produce a burning sensation on contact with cold. Symptoms
have developed in otherwise healthy people after sexual inter-
course with someone with ciguatera poisoning, showing that
the toxin may be sexually transmitted. (However, it is not clear
why someone with those symptoms would be in the mood for
having sex.) Diarrhea and rashes have been reported in breast-
fed infants of poisoned mothers, suggesting that the toxins get
into breast milk. The symptoms last from weeks to years, and
in extreme cases up to 20 years, often leading to long-term dis-
ability. Most people recover slowly over time, but some patients
recover and then subsequently get recurring symptoms. Unlike
beds of sedentary shellfish that can be monitored and closed
when HAB toxins are found, fish are very mobile and the occur-
rence of ciguatera is very spotty. In addition, the Gambierdiscus
don't need to bloom in order for fish to become contaminated.
In a trawl full of fish caught at a given location, some may have
ciguatera while others of the same species and size will not.
Therefore it is very difficult to monitor it and reduce the occur-
rence of this debilitating disease. Although sensitive labora-
tory analyses can detect and confirm CTX in fish, no practical
field tests are available for monitoring programs and detecting
CTX in fish quickly enough before it would spoil. Prevention
depends on educating the public, seafood suppliers, and dis-
tributors about known ciguatera areas and high-risk fish spe-
cies. The only sure way to prevent it is to not eat fish when in
the tropics—this is hardly a satisfactory solution to the problem.
How can the incidence of poisoning by marine toxins
be reduced?
Ongoing surveillance and rapid detection are essential to
reduce the incidence of poisonings. However, conventional
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