A study published in the American Journal of Tropical Medicine and Hygiene indicates that Ciguatera, a perilous toxin present in tropical reef fish like the barracudas, has been making more people sick than previously thought.

Ciguatera can neither be frozen or cooked out of an infected fish nor can be smelt or seen with naked eye. While some people eating fish infected by the toxin don’t experience any symptom, there are many who develop symptoms that end up lasting for weeks and at times even months.

Some of the common ill effects of the toxin are diarrhea, severe vomiting, a tingling sensation in the mouth, and so on. Toxic fish poisoning due to Ciguatera might also make one experience a temperature reversal. For those who don’t know: a victim of temperature reversal would feel hot when touching something cold and vice-versa.


There are some small fish that nibble on the coral reef algae, organisms known for being rich sources of ciguatera. These small fish are consumed by bigger fish like barracudas. According to the lead author of the study Elizabeth Radke, the concentration of the toxin increases as it move upwards, which makes eating the bigger fish more dangerous. Radke is an epidemiologist at the Emerging Pathogens Institute of the University of Florida.

The study says that the Hispanics are at maximum risk of developing food poisoning from ciguatera. The researchers have written that this may be because the Hispanics have greater tendency of eating barracudas than other known demographic groups.

The other fish species that might make people suffer from toxic fish poisoning include hogfish, amberjack, and grouper. Fish such as mahi mahi, mackerel and snapper can also cause toxic poisoning, but to a much letter extent.

It’s true that Radke and his team haven’t asked people to stay away from all tropical reef fish. However, the researchers have made it clear that when one eats a large, carnivorous fish dwelling in the waters of subtropical or tropical areas such as South Florida, he or she should know that there’s a risk.

Must Read: Toxic fish poisoning more common in Florida, study finds

According to Radke, people who fall ill after eating these fish should see a doctor immediately and inform him/her that they have consumed saltwater fish.

During the study, the researchers analyzed 291 cases in Florida taking place between 2000 and 2011. They also surveyed over 5,000 licensed saltwater fishers through emails. The results of these analyses and surveys revealed that ciguatera is responsible for causing 5.6 cases of food poisoning per 100,000 people. This number is much higher than the previous estimate of 0.2 cases in every 100,000 people.

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