Concerning new findings reveal public health records have most likely underestimated the number of people in Florida who have fallen ill after consuming local fish that carry a dangerous food-borne toxin.
The analysis by researchers at the University of Florida's Emerging Pathogens Institute and the Florida Department of Health found the state's annual incidence of poisoning with the toxin ciguatera is at about 5.6 cases per 100,000 people; previous estimates have suggested an incidence rate of only .2 cases per 100,000 derived from the reports physicians submit to the Department of Health.
The ciguatera toxin causes symptoms such as severe nausea, vomiting, and even neurological symptoms. The contaminant has been known to be found in local Florida fish such as barracuda, grouper and amberjack, but the new data indicates it can also be carried by hogfish, snapper, mackerel and mahi mahi.
"I think there is a broader awareness the farther south you go that barracuda are carriers but perhaps not as much awareness that a fish like grouper or amberjack can carry ciguatera," said Elizabeth Radke, the lead author of the study. "I don't think that people necessarily need to stop eating these other fish," she added, "but they need to be aware there is a risk, and if they start feeling sick after eating, they should see a physician."
According to state health records, each year ciguatera infects about one out of every 100,000 people in Miami-Dade and three out of every 100,000 in Monroe County; these new findings show the numbers are closer to 28 per 100,000 in Miami-Dade and 84 per 100,000 in Monroe. The new findings were made by looking at a survey of thousands of recreational saltwater anglers across the state, which showed a high number of self-identified cases that had not been reported to the Department of Health.
Ciguatera originates in algae that grow on coral reefs in warm tropical and subtropical waters, and is transmitted to fish when they feed on this infected marine greenery or a smaller fish that has already been contaminated.
The researchers noted there are concerns warming ocean waters caysed by climates change could be causing this toxin to migrate northwards.
"There have been cases reported as far north as Georgia and South Carolina, but those likely involved fish that picked up the poison in South Florida or the Caribbean and migrated north," Radke said. "But there needs to be continued surveillance at the toxin's geographic borders."
The findings were reported in a recent edition of the American Journal of Tropical Medicine and Hygiene.
