Ciguatera, occurrence

The occurrence of 12 and 13 in fish but not in G. toxicus implies that CTX-3C 14 produced by this dinoflagellate was oxidized in fish to 12 and 13, supporting the theory for oxidative modification of ciguatera toxins during the food chain transmission. 

Unlike PSP, there is a firm body of evidence that documents the occurrence of hypotension and bradycardia with severe ciguatera. Katz, for example, reported bradycardia for 66% and hypotension for 27% of cases in Hawaii [65] while Bagifis reported bradycardia for 14% and hypotension for 12% of cases in the South Pacific [79]. One report suggests that hypotension in ciguatera results from parasympathetic excess and sympathetic failure [83]. Occasionally tachycardia has occurred as well. 

Gillespie NC, Lewis RJ, Peam JH, Bourke ATC, Hohnes MJ, Bourke JB, Shields WJ. Ciguatera in Australia occurrence, clinical features, pathophysiology and management. MedJAust 145 584—590, 1986. 

Kwan LC, Cheung DK, Kam KM. Peak occurrences of ciguatera fish poisoning precede cholera outbreaks in Hong Kong. Epidemiol Infect 131 621-626, 2003. 

McFarren, E.F. et al.. The occurrence of a ciguatera-like poison in oysters, clams, and Gymnodinium breve cultures, Toxicon, 3, 123, 1965. 

Despite frequent occurrences of ciguatera toxins in many parts of the world, this poisoning is rarely fatal, because of the low concentration of the toxin in fish flesh. Maybe for this reason very few specific regulations exist for ciguatera toxins [6]. In some areas, public health measures have been taken that include bans on the sale of high risk fish from known toxic locations. Such bans have been used in American Samoa, Queensland, French Polynesia, Fiji, Hawaii, and Miami. The bans were apparently with some success but with attendant economic loss [38]. 

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