While nausea and vomiting are classic symptoms of common foodborne illness such as Escherichia coli (E. coli) or Salmonella enterocolitis infections, tingling toes and fingers are a sign of a more severe form of foodborne illness called ciguatera fish poisoning.
The single-celled ciguatoxin-producing protozoan, the dinoflagellate Gambierdiscus toxicus, lives on algae in tropical, coral-reef waters. Small herbivorous fish eat this algae as part of their diet. As nature would have it, these small fish are part of part of the diet of larger, carnivorous fish — and so on through the food chain. Eventually, we arrive at the large reef fish we commonly consume: barracuda, black grouper, blackfin snapper, cubera snapper, dog snapper, greater amberjack, hogfish, horse-eye jack, king mackerel and yellowfin grouper [source: CDC].
And while ciguatoxin is harmless to fish, it's fatal to humans. It's impossible to detect ciguatoxin contamination by a fish's color, odor or taste. And cooking fish at high temperatures or freezing it won't remove the toxins. This biotoxin affects the body's gastrointestinal system first, before causing neurological symptoms such as a "pins and needles" feeling or tingling, called paresthesias. The classic symptom of this infection is neurological: paradoxical temperature reversal, which means hot things feel cold and cold things feel hot. Cardiovascular symptoms are also common and may include hypotension and pulmonary edema.
Symptoms may appear as quickly as 15 minutes after ingesting the toxin, although, most commonly symptoms appear between six and 12 hours. There is no treatment, and while symptoms have been known to last for days, for some people it can take years to recover.