[Intoxication by marine animal venoms in Madagascar (ichthyosarcotoxism and chelonitoxism): recent epidemiological...

If seafood poisonings are well documented in the Pacific region, they are not often reported in the Indian Ocean. In Madagascar, fishermen and people living in coastal areas are traditionally aware of seafood poisonings. Mass intoxications were described in the sixties, including lethal cases following sardine ingestion. From 1989 to 1993, 28 ichtyosarcotoxism cases, mainly ciguatera occurring in children, were reported in Tulear hospital. From July 1993 to May 1996, nine seafood poisoning outbreaks occurred in coastal villages after turtle, shark and sardine meals. Clinical symptoms were related to marine toxins. For turtle intoxications, gastro-intestinal symptoms are the most frequently seen (acute stomatitis, dysphagia, vomiting and diarrhea), with case fatality rates around 7%. For shark intoxications, the most frequent symptoms were neurologic (paresthesia specially peribuccal and extremities), and gastro-intestinal (diarrhea and vomiting), with specific case fatality rates varying from 0% to 30%. For sardine intoxication, symptoms were gastro-intestinal (vomiting) and neurologic (paresthesia), and from the two intoxicated people one died. Two previously unknown biotoxins were isolated from the liver of a shark responsible for a mass poisoning, namely carchatoxins. For the turtles, the search of chelonitoxin is under way. For the sardines, clupeotoxin was isolated. Because of the frequency and the gravity of collective seafood poisonings occurring in recent years, the Ministry of Health has implemented a Seafood Poisoning National Control Programme. This programme is based on three major strategies: the setting of an epidemiological surveillance network, the prevention of the communities through educational programmes, and the development of research on marine eco-environment.