Ciguatera, first recognized in the 1550s in the Caribbean (NRC 1999), is a form of ichthyotoxism caused by the consumption of mainly reef fish contaminated with the ciguatoxin class of lipid soluble toxins. An estimated 50,000 victims worldwide annually are reported with 20,000-30,000 cases of ciguatera in the Caribbean in Puerto Rico and U.S. Virgin Islands (Anon. 1997; Bomber and Aikman 1988/89 cited in NRC 1999). Only 20-40% of cases are estimated to be reported (NRC 1999). The toxins causing ciguatera have been identified by the primary vector, the dinoflagellate Gambierdiscus toxicus, an epiphyte living on a range of calcareous macroalgae and other substrates on coral reefs. G. toxicus is widely distributed on coral reefs and lagoons but is most prolific in shallow waters (3-15 m) away from terrestrial influences. Herbivorous reef fish browsing on reef algae ingest G. toxicus and concentrate the ciguatoxins in the gut and muscle tissue. Piscivorous reef fish may then become toxic through the consumption of herbivorous fishes and the concentration of the toxins up the food web. Other benthic dinoflagellates such as Prorocentrums, Ostreopsis and Coolia are also linked to ciguatera outbreaks (Tosteson et al. 1988; NRC 1999).

Ciguatoxins are not destroyed by cooking and no routine tests are performed to identify contaminated fish, or to predict the timing or occurrence of ciguatera outbreaks on reefs. Ciguatera poisonings are characterized by a range of often severe gastrointestinal and neurological symptoms. Intoxicated individuals may experience diarrhea, vomiting, lethargy, numbness, reversal of temperature perception, itching, tingling and muscular pains. Some of these symptoms such as itching and muscular pain may persist for several months. A recurrence of neurological symptoms may be brought on by consumption of alcohol or certain foods such as other fish, fish-flavored food products, peanut butter, and meat such as chicken and pork. A thorough review of the clinical, epidemiological and ecological aspects of ciguatera has been given by Lewis and Holmes (1993).

The occurrence of ciguatera is documented in the central Pacific and the Caribbean. Ciguatera is rarely fatal and in most areas, local people know where ciguatera ‘hotspots’ occur and which species of fish are likely to be contaminated at certain times of the year. However, there have been increasing reports of the occurrence of ciguatera poisoning in places especially in Asia, which are outside the range where this disease normally occurs. It is speculated that these cases are caused by fish obtained from local traders in high-risk areas in the Pacific and brought to markets such as Hong Kong without proper verification of its origin. Over 400 persons experienced ciguatera poisoning in 1998 in Hong Kong (Sadovy 1999). Even if such cases remain rare in a large market such as Hong Kong, they pose a real threat to the commercialization of fish as a whole, as wary consumers might become reluctant to purchase any fish, if they cannot be assured that is free of ciguatera toxin. A number of trade regulations, e.g., United States Food and Drug Administration, 1999 Food Code-HACCP guidelines and the European Communities Directive 91/493/EEC address the trade of species that are affected (Sadovy 1999).

So far, little attempt has been made to document systematically the occurrence of ciguatera. Most information on ciguatera from the Pacific has been reported through epidemiological records from hospitals, which simply report the number of cases of fish poisoning treated in a given year. Accurate documentation of ciguatera case histories has been confined in the past mainly to French Polynesia, Australia and Hawaii.

In 1990, the then South Pacific Commission (SPC, now called Secretariat of the Pacific Community) commenced collecting detailed case histories of ciguatera poisonings from the Pacific Islands and summarizing these in a database format (Dalzell 1992, 1993). Brody (1972) and Olsen et al. (1984) provide an overview of the ciguatera problem in the Caribbean.

FishBase summarizes published reports on fish species, which have been observed to have caused ciguatera poisoning in given countries. As mentioned above, the occurrence of ciguatera contamination in fish is usually very localized, thus the inclusion of a fish species in the listing should in no way be interpreted as all fish of that species in the mentioned country being unfit for human consumption.

In addition to published records, FishBase also has incorporated parts of the SPC database on case histories in the Pacific area to provide more detailed information on the possible causes and effects of ciguatera poisoning. Reporting of these case histories, however, has been uneven, with many case histories reported from Tuvalu and New Caledonia, but with few, if any, from locations such as the Marshall Islands and Kiribati, which are known to have chronic problems with ciguatera outbreaks.

A ciguatera occurrence record for a given fish species contains the following fields:

Country: The name of the country where the ciguatera poisoning was observed.

Distribution: An indicator of the geographic dimension of the problem at national level with the options being: nation-wide; regional; localized; or not stated in the absence of any such information.

Frequency: An indicator of the frequency with which the occurrence of ciguatera is observed in the species in question, the options being: frequent; occasional; rare; or not stated in the absence of any such information.

Remarks: Any additional information that allows identifying more precisely the locality within a country from where the specific record originated.

If the selected record is part of the SPC database (Dalzell 1992, 1993), clicking on the button More Information gives access to the additional information provided through this database. The various fields in the database contain replies to a questionnaire conducted with persons who have become sick after eating a fish or other marine organism (though records from non-fish species have been omitted from the listings provided in FishBase).

The questionnaire had been structured around the following topics: Type of food, type of locality from where the offending food item originated, how the food item had been preserved, which part of it was eaten, and in what way it was prepared, as well as general information such as date and number of people who became affected.

Clicking on the button Symptoms & Medical data provides, if available, detailed information on 18 symptoms reported by patients (such as burning/pain when touching cold water; tingling/numbness sensations; difficulty in breathing, walking; or talking; skin itching; diarrhea; vomiting; etc.).

FishBase contains some 350 records of individual fish species being reported as (potential) carriers of ciguatera in specified countries. These records are comprised of published information in the literature and those from the SPC ciguatera database. The latter includes over 600 records, of which around 10% refer to non-fish species or organisms which have not been identified. These have generally been excluded from the listings as have, for the sake of clarity, multiple occurrences of the same combination of species and location. As stated earlier, the SPC database for the Pacific region is to some extent biased, as reporting has been very uneven, with over 50% of case histories coming from Tuvalu, and most of these from the island of Niutao. Part of the problem in obtaining case history records lies in the blurring of responsibility for ciguatera outbreaks between fisheries and health administrations in the Pacific Islands. Further, ciguatera is not seen as a priority health issue in most locations and only generates concern in fisheries administrations when it has a detrimental influence on export of fish to metropolitan countries.

Where possible, local species names have been translated into their scientific equivalent, although in many instances, a local name refers to a genus or family of fish rather than species. This is one of the reasons why the CIGUATERA table is not only linked with the SPECIES table, but also with the FAMILIES and COUNTRY tables. The SPC will update this database as new cases from the Pacific Islands accumulate. Moreover, the FishBase Team invites colleagues working in the Caribbean to contribute records that would allow this database to expand, and eventually, to cover all areas of the world where ciguatera occurs on the ‘Search FishBase’ page.

In the FishBase CD-ROM version, the CIGUATERA table can be accessed in several ways:

When within the CIGUATERA table, clicking on the Map button shows all countries highlighted, where the selected species has been reported as carrier of the ciguatera toxin. Note that these countries are usually small island states and thus barely visible on the scale of a world map. Using the zoom function provided in WinMap might be necessary for better viewing.

In FishBase on the Web, click on the Ciguatera radio button in the ‘Information by Topic’ section.

Anon. 1997. Ciguatera for health care professionals. Sea Grant in the Caribbean. Jan.-March, p.5.

Brody, R.W. 1972. Fish poisoning in the Eastern Caribbean. Proc. Gulf Caribb. Fish. Inst. 24: 100-116.

Dalzell, P. 1992. Ciguatera fish poisoning and fisheries development in the South Pacific. Bull. Soc. Pathol. Exot. 85 (5): 435-444.

Dalzell, P. 1993. Management of ciguatera fish poisoning in the South Pacific. Mem. Queensland Mus. 34(3): 471-480.

Lewis, R.J. and M.J. Holmes. 1993. Origin and transfer of toxins involved in ciguatera. Comp. Biochem. Physiol. 160C(3): 615-628.

National Research Council (NRC). 1999. From monsoons to microbes: understanding the ocean’s role in human health. National Academy Press, Washington, D.C. 132 p.

Olsen, D.A., D.W. Nellis and R.S. Wood. 1984. Ciguatera in the Eastern Caribbean. Mar. Fish. Rev. 46(1): 13-18.

Sadovy, Y. 1999. Ciguatera – a continuing problem for Hong Kong’s consumers, live reef fish traders and high-value target species. SPC Live Reef Fish Info. Bull. No. 6. (December 1999):3-4.

Tosteson, T.R., D.L. Ballantine and H.D. Durst. 1988. Seasonal frequency of ciguatoxic barracuda in Southwest Puerto Rico. Toxicon. 26(9):795-801.