Ciguatera fish poisoning: a major common-source outbreak in the U.S. Virgin Islands

An Updated Review of Ciguatera Fish Poisoning: Clinical, Epidemiological, Environmental, and Public Health Management

Ciguatera Fish Poisoning (CFP) is the most frequently reported seafood-toxin illness in the world. It causes substantial human health, social, and economic impacts. The illness produces a complex array of gastrointestinal, neurological and neuropsychological, and cardiovascular symptoms, which may last days, weeks, or months. This paper is a general review of CFP including the human health effects of exposure to ciguatoxins (CTXs), diagnosis, human pathophysiology of CFP, treatment, detection of CTXs in fish, epidemiology of the illness, global dimensions, prevention, future directions, and recommendations for clinicians and patients. It updates and expands upon the previous review of CFP published by Friedman et al. (2008) and addresses new insights and relevant emerging global themes such as climate and environmental change, international market issues, and socioeconomic impacts of CFP. It also provides a proposed universal case definition for CFP designed to account for the variability in symptom presentation across different geographic regions. Information that is important but unchanged since the previous review has been reiterated. This article is intended for a broad audience, including resource and fishery managers, commercial and recreational fishers, public health officials, medical professionals, and other interested parties.

A veterinary guide to the fish gastrointestinal tract

For veterinarians to better understand aquatic animal health, the most basic veterinary foundation begins with understanding piscine anatomy and physiology. General observations of fish behavior, anatomy, and food apprehension can provide more valuable diagnostic information than advanced laboratory testing alone. This article highlights anatomic differences of fish species occupying different environmental niches, using a case to show the use of modern veterinary diagnostics, and introduces additional topics in piscine gastroenterology related to toxins, nutrition, probiotics, and infectious diseases.

Association of cardiac disease and alcohol use with the development of severe ciguatera

OBJECTIVES

Ciguatera is a foodborne illness that causes severe gastrointestinal and neurologic symptoms, but the risk factors for illness are not well established.

METHODS

In St Thomas, US Virgin Islands, we performed a case-control study for ciguatera, enrolling 47 patients primarily through the emergency department and 141 age- and sex-matched controls identified through an island-wide survey. We used conditional logistic regression to assess health-related risk factors for ciguatera, including comorbidities and alcohol and tobacco use.

RESULTS

Cases were more likely than controls to report alcohol consumption at least weekly (odds ratio 5.7, 95% confidence interval 2.7-24.8). Cases also more frequently had a history of heart disease (odds ratio 6.3, 95% confidence interval 1.2-32.7). Previous ciguatera episodes, lower levels of education, and frequent fish consumption also were associated with illness.

CONCLUSIONS

This study provides preliminary evidence that preexisting health status influences an individual's risk of developing severe ciguatera. There may be a benefit to educating high-risk individuals about preventing ciguatera.

Ciguatera fish poisoning: treatment, prevention and management

Ciguatera Fish Poisoning (CFP) is the most frequently reported seafood-toxin illness in the world, and it causes substantial physical and functional impact. It produces a myriad of gastrointestinal, neurologic and/or cardiovascular symptoms which last days to weeks, or even months. Although there are reports of symptom amelioration with some interventions (e.g. IV mannitol), the appropriate treatment for CFP remains unclear to many physicians. We review the literature on the treatments for CFP, including randomized controlled studies and anecdotal reports. The article is intended to clarify treatment options, and provide information about management and prevention of CFP, for emergency room physicians, poison control information providers, other health care providers, and patients.

Marine Neurotoxins: Ingestible Toxins

Fish and shellfish account for a significant portion of food-borne illnesses throughout the world. In general, three classes of diseases result from seafood consumption--intoxication, allergies, and infections. In this review, the authors discuss several seafood-borne toxins, including domoic acid, which acts on the central nervous system. In addition, the authors discuss ciguatoxin-, brevetoxin-, saxitoxin-, tetrodotoxin-, and scombroid-related histamine toxicity, all of which act primarily on the peripheral nervous system. Fish has become a very popular food in the US mostly related to its potential health benefits. Fish is consumed to such a degree that fishing stocks are reportedly at an all time low from what seemed like an endless supply even 30 years ago. One of the most significant threats to human intoxication is the recreational harvest of shellfish, often times located in remote locations where the harvesters are subsistent on fishery resources and have no monitoring in place. The hazard to intoxication is not as common in purchased seafood, which is more stringently regulated, yet still is a serious problem. Most ingestible toxins are thermo-stable and therefore unaffected by cooking, freezing, or salting. Air transport of consumable products throughout the world makes it easy to obtain exotic edibles from far away countries. A seemingly unusual toxin can be more commonly encountered than previously thought and it is important to consider this when evaluating patients. Recognition and treatment of various neurologic symptoms related to seafood ingestion is paramount in today's mobile, gastronomic world. Specific treatments vary with each individual toxin and with the individual's specific reaction to the toxin. Generally, some degree of medical care is required with all ingestible toxin exposure, ranging from simple administration of medication and hydration to ventilatory and cardiovascular support.

Ciguatera fish poisoning in the Caribbean islands and Western Atlantic

Ciguatera fish poisoning (ciguatera), a common poisoning caused by fish ingestion, is reviewed in the Western Atlantic and the Caribbean waters. It is endemic from Florida coasts (northern limit) to Martinique Island (southern limit), with outbreaks occurring from time to time. In the Caribbean, ciguatera causes a polymorphic syndrome with gastrointestinal, cardiovascular, and neurological signs and symptoms. Neurological and muscular dysfunctions can be treated by intravenous injection of D-mannitol. The lipid-soluble toxins involved are ciguatoxins that are likely produced by the dinoflagellate Gambierdiscus toxicus. G. toxicus strains are endemic in the Caribbean Sea and in theWestern Atlantic. Although it is likely that blooms of G. toxicus are ingested by herbivorous fishes, they are not implicated in ciguatera in the Caribbean. Rather, large carnivores (barracudas, jacks, snappers, groupers), consumers of smaller benthic fish, are often involved in ciguatera. Fish toxicity depends on fishing area and depth, fish size and tissues, and climatic disturbances. Ciguatoxins have been isolated and purified from Caribbean fish species. The structure of two epimers, C-CTX-1 and C-CTX-2 from horse-eye jack, comprise 14 trans-fused ether-linked rings and a hemiketal in terminal ring. Caribbean ciguatoxins are mainly detected in the laboratory by chicken, mouse, mosquito, or cell bioassays, and by analytical HPLC/tandem mass spectrometry down to parts per billion (ppb). A ciguatera management plan that integrates epidemiology, treatment, and a simple method of detection is required to ensure the protection of consumers.

Mild ciguatera poisoning: Case reports with neurophysiological evaluations

Ciguatera poisoning causes mainly gastrointestinal and neurological effects of variable severity. However, symptoms of peripheral neuropathy with paresthesias and paradoxical disturbance of thermal sensation are the hallmark. Electrophysiological studies are often normal, except in severe cases. We report four people who developed mild ciguatera poisoning after barracuda ingestion. Electrophysiological studies documented normocalcemic latent tetany. These findings are consistent with ciguatoxin's mechanism of toxicity, which involves inactivation of voltage-gated Na(+) channels and eventually increases nerve membrane excitability.

Biological neurotoxins

The authors divide biological toxins into animal, plant, and bacterial classes and discuss each within a context of demographic, clinical and research examples. Advances in our knowledge are highlighted, and the authors relate the implications of this knowledge to target-specific neurologic involvement.

Poisonings: food, fish, shellfish

Not every traveler who gets sick away from home has an infection; some are poisoned. This article describes common and dangerous illnesses caused by food-borne toxins. It explores the toxic illnesses acquired from fish or seafood, including scombroid, ciguatera, pufferfish toxicity, and a variety of shellfish poisonings. It also provides a brief overview of plant toxicity. Although gastroenteritis is a common feature of many food poisonings, this article emphasizes those processes associated with neurologic manifestations, as they tend to be more dangerous to patients and less well understood by physicians. It also stresses strategies to prevent food poisoning.

Ciguatera fish poisoning: treatment with intravenous mannitol

Intravenous mannitol was given to 16 patients with acute ciguatera fish poisoning requiring hospital admission. Thirteen patients (81%) presented with sensory and neuromuscular symptoms; paraesthesiae and pain and weakness in the lower limbs were predominant features. Mannitol had little effect upon gastrointestinal manifestations, but a marked reduction was observed in the expected duration of neurological symptoms. Although these results are empirical and uncontrolled, they suggest that mannitol infusion may be effective in altering the clinical course of acute ciguatera fish poisoning.

Polyneuropathy secondary to ciguatoxin poisoning

Following ingestion of marine fish in Thailand this patient complained of gastrointestinal and neurological disturbances, marked by severe, mainly motor, demyelinating polyneuropathy, which worsened on her return to Italy a few days later. The clinical pattern, electromyography, cerebrospinal fluid test and sural nerve biopsy by electronmicroscopy permitted the diagnosis of polyneuropathy secondary to ciguatoxin poisoning.

Treatment of ciguatera fish poisoning with amitriptyline and nifedipine

Ciguatera fish poisoning is the most common fish poisoning in the United States. Symptoms involve the gastrointestinal, cardiovascular and neurological systems. No known treatment exists. We explore the therapeutic effect of amitriptyline in two patients and nifedipine in one patient. Amitriptyline demonstrated resolution of most symptoms except for heat/cold reversal in one patient and heat/cold reversal, pruritus and headache in the second patient. We then used nifedipine in the second patient and noted only the resolution of his headaches. We recommend further study of these agents for the treatment of ciguatera fish poisoning.

Ciguatoxin from the flesh and viscera of the barracuda, Sphyraena jello

Five of six barracuda, Sphyraena jello, captured in the same area of Queensland as toxic Spanish mackerel (Scomberomorus commersoni) were found to be toxic. One major lipid-soluble toxin, present in both the flesh and viscera of a pooled sample of barracuda, was chromatographically indistinguishable from Spanish mackerel flesh ciguatoxin. Signs and symptoms induced by toxic barracuda in humans were typical of ciguatera and cats and mice displayed signs indistinguishable from those induced by Spanish mackerel ciguatoxin. Purified barracuda ciguatoxin had an i.p. LD50 to mice of 55 micrograms/kg. Barracuda ciguatoxin had a narrow range (0.7-1.4 mouse units) of doses between 0% and 100% lethality and its dose vs. death-time relationship was similar to the relationship produced by moray eel and Spanish mackerel ciguatoxin. No water-soluble toxins were detected in the viscera of these barracuda, but a less polar lipid-soluble toxin was found in the viscera. This minor toxin represented 14% of the total viscera lethality and induced signs in mice similar to the major toxin. Barracuda could be an important link in the transfer of ciguatoxin to large Spanish mackerel in southern Queensland waters.

An analysis of poison control center reports of ciguatera toxicity in Puerto Rico for one year

Forty-five cases of ciguatera poisoning in Puerto Rico (P.R.) are described. These cases represent all those reported to the P.R. Poison Control Center in 1982. Most of the cases were reported in the spring and summer months. The most common fish ingested was the grouper. The clinical presentation of acute and long term symptoms was similar to that reported in other geographical areas, except the incidence of paresthesias. Paresthesias were reported in 11% of the patients reported to the poison center. A companion telephone survey indicated that persons in P.R. that do not eat fish do so because of fear of ingesting the toxin. Our findings indicate an overall familial contact with the ciguatera toxin in Puerto Rico at 7%. This study is the first to document that ciguatera is a common poisoning reported to the Poison Control Center in Puerto Rico. Our findings also support other authors contentions of geographical variations in clinical symptomatology.