High fish consumption in French Polynesia and prenatal exposure to metals and nutrients.

French Polynesians consume high quantities of fish and are therefore exposed to seafood-related contaminants such as mercury (Hg) or lead (Pb) and nutrients such as iodine, selenium and long chain polyunsaturated fatty acids (LC-PUFAs). As the developing foetus is sensitive to contaminants and nutrients, a cross-sectional study was conducted in French Polynesia in 2005-2006 to assess prenatal exposure to contaminants and nutrients through fish consumption. Two hundred and forty one (241) delivering women originating from all islands of French Polynesia were recruited and agreed to answer questions on fish consumption and gave permission to collect umbilical cord blood for metals and nutrients analyses. All parameters were found in high concentrations in cord blood samples except for lead. Mercury concentrations averaged 64.6 nmol/L (or 13 microg/L) with values ranging from 0.25 to 240 nmol/L. Of the sample, 82.5% had Hg concentrations above the US-EPA blood guide-line of 5.8 microg/L. Tuna was the fish species which contributed the most to Hg exposure. High selenium and LC-PUFAs may counterbalance the potential risk of prenatal exposure to Hg in French Polynesia. Due to the high fish consumption of mothers, Polynesian newborns are prenatally exposed to high doses of mercury. Although selenium and omega-3 fatty acids may counteract mercury toxicity, informing pregnant women on both the mercury and nutrient content of local fish species is important.

Prevalence of chronic symptoms of ciguatera disease in French Polynesian adults.

Ciguatera is a tropical disease caused by seafood poisoning, for which the duration of symptoms remains to be determined. The objectives of this prospective study were to determine the prevalence of symptoms at different time points and to identify factors associated with chronic symptoms observed in adults suffering from this disease. At the time of onset, we observed a dose-response relationship including a strong association between the delay of appearance of symptoms and a severity index (P < 0.001). Our results confirmed the key role of fish organs in the risk of contracting a more severe form of ciguatera. In the chronic stage, only the severity score based on information recorded in the acute phase is related to the persistence of symptoms (P < 0.001). Our findings suggest that several symptoms observed in the acute phase of the disease are still experienced 15 days after onset. This supports previous observations based on isolated case reports.

Temporal trends and epidemiological aspects of ciguatera in French Polynesia: a 10-year analysis.

OBJECTIVES: The purpose of this study was to report the temporal trends of the incidence of ciguatera poisoning from 1992 to 2001 in French Polynesia. METHODS: This retrospective study analysed 7842 cases of ciguatera disease recorded over a period of 10 years. RESULTS: The annual incidence varied from 26.3 to 41.9 per 10,000 person-years. An analysis of cases grouped by archipelago revealed differences in incidences (P < 0.0001) with the most remote archipelagos having the highest incidences. A detailed analysis on a sub-sample of recorded cases for which clinical information was available (n = 1824) confirmed the neurological and gastrointestinal nature of this seafood poisoning. CONCLUSION: The incidence of ciguatera poisoning appeared relatively stable during the 10 years of the study period. However, the gradient of remoteness observed suggests an adaptation of management of ciguatera disease to each archipelago.