The number of people sickened by eating fish such as barracuda and other sport fish is far greater than scientists previously believed, federal health officials warned Tuesday. Researchers say the illnesses are linked to a toxin in the fish, citing a new study documenting cases of ciguatera fish poisoning in Florida.
According to the U.S. Centers for Disease Control and Prevention (CDC), ciguatera fish poisoning is an illness caused by eating fish that contain toxins produced by Gambierdiscus toxicus, a relatively rare marine microalgae.
People sickened with ciguatera usually experience nausea, vomiting, and neurologic symptoms such as tingling sensations, especially in the fingers or toes. The sickness may also distort the person’s sense of touch and confuse their perceptions of hot and cold. There is no cure for the illness, which can last for years, but symptoms usually go away in a few days or weeks.
Researcher Elizabeth Radke’s study, published June 29 in the American Journal of Tropical Medicine and Hygiene, found the rate of illness to be substantially higher than previously estimated, with areas around Miami and in the Florida Keys to be the most affected.
Rates of ciguatera poisonings were highest among the Florida’s Hispanic population, possibly because of cultural tendencies to eat barracuda, Dr. Radke said.
She said that consumers should avoid eating barracuda, but noted that the toxin is also found in other types of Florida fish, including grouper, amberjack, hogfish, mackerel , mahi mahi, and snapper. Most of the fish causing infections in Florida are caught in the Bahamas and the Florida Keys, the researchers concluded.
Researchers from the University of Florida’s Emerging Pathogens Institute and the Florida Department of Health surveyed thousands of recreational salt-water fishermen in the state and compared those figures with public health records.
The resulting data showed that there were about 5.6 cases of ciguatera per every 100,000 people in Florida — 28 times higher than the previously estimated 0.2 cases per 100,000 state residents. Researchers attributed the discrepancy to anglers not reporting their illness. Doctors misidentifying the illness was another factor.
According to the study, ciguatera poisoning is the most common form of fish-related food poisoning in the world. The toxin is usually found in algae growing on coral reefs in warm tropical and subtropical ocean waters, a prime food source for fish. The highest risk of ciguatera poisoning is in fish from the Caribbean Sea, the Pacific Ocean, and the Indian Ocean.
Although the risk of contracting ciguatera is higher than scientists once thought, Dr. Radke said there is no need for people to stop eating other types of fish besides barracuda. But she added that they should be aware of the risk and see a doctor is they begin to feel sick after eating the fish.