Ciguatera Fish Neurotoxin Poisonings Surge in New York City

Karyn Hede

February 04, 2013

A cluster of reports of neurological and cardiovascular symptoms among people eating reef fish in New York City (NYC) has revealed an increase in ciguatera, a foodborne illness caused by eating certain fish contaminated with neurotoxins, according to a report published in the February 1 issue of the Morbidity and Mortality Weekly Report. The sudden surge prompted the NYC Department of Health and the Centers for Disease Control and Prevention to issue a report detailing the cases. During a single year between August 2010 and July 2011, NYC had 28 confirmed ciguatera fish poisoning cases — more than occurred in the previous 10 years combined.

In the confirmed NYC cases, people had eaten barracuda and grouper, large predatory reef fish that concentrate certain toxins in their flesh that are harmless to the fish but that cause neurological and cardiovascular symptoms when ingested in sufficient quantities. Symptoms of ciguatera often mimic other forms of food poisoning within the first 24 hours of ingestion, making diagnosis difficult. Patients reported acute gastrointestinal symptoms including vomiting, diarrhea, and abdominal pain, which generally resolved within the first few days.

Diagnostic symptoms in the NYC cluster included neurological symptoms such as a feeling of loose teeth, tingling of the mouth and extremities, and cardiovascular symptoms, including hypotension with slow heart rate (bradycardia), after the onset of gastrointestinal symptoms. Other common symptoms can include paresthesias, including feelings of burning, prickling, and itching skin, and reverse temperature sensation. Neurological symptoms last for several weeks but can persist for months. Supportive care is the only available treatment.

Because the toxins are colorless, odorless, and tasteless and are not destroyed by cooking, they are difficult to detect. There is currently no field test for the toxins available. Confirmation of poisoning requires sending samples of suspected contaminated fish to a laboratory equipped with specialized testing capabilities.

Prevention requires educating people to the risk of eating coral reef fish such as barracuda, grouper, snapper, amberjack, and surgeonfish that are caught in areas known to be contaminated, such as the waters off south Florida and the Caribbean. However, many of the people in the NYC cases did not know they were eating barracuda, according the official NYC report. In the NYC cases, officials traced the fish in the 4 separate incidents to different NYC suppliers and several Florida distributors.

The authors have disclosed no relevant financial relationships.

Morb Mortal Wkly Rep. 62;4:61-65. Full text