Ciguatera fish poisoning in industrial ship crewmembers: a retrospective study in a seaport general practice in Trinidad and Tobago.

The objective of this study was to outline the epidemiology of Ciguatera fish poisoning as seen in a general practice serving two industrial seaports in Trinidad and Tobago, in order to highlight the potential public health implications. A retrospective study was undertaken of all the cases of Ciguatera fish poisoning identified between November 1, 1992 and October 31, 1998 in a seaport general practice to identify signs, symptoms and treatment. An investigation of one outbreak was undertaken. Four outbreaks affecting 42 male ship crewmembers were identified. The suspect fish were caught in northern Caribbean waters en route to Trinidad and Tobago. The most common early symptoms were diarrhoea, vomiting, abdominal cramps, pruritus and tiredness. In the third outbreak, dysaesthesia was common. Progression to muscular weakness, ataxic gait, unsteadiness and other neurotoxic signs were seen in moderate to severe disease. Hypotension was an important prognostic sign in the initial case. Treatment was symptomatic and supportive and included vitamins B12 and BCO, folic acid, prostigmine, steroids and antihistamines as indicated. In the investigation of the second outbreak, the relative risk of 'eating fish meat' was 5 (95% CI 1.45, 17.27, p < 0.0001). Abdominal symptoms, pruritus, and muscle weakness with a history of consuming a fish-meal were diagnostic indicators of 'ciguatera fish poisoning.' All cases were industrial ship crewmembers. It is suggested that increased clinician awareness with early and appropriate treatment, and focussed public health intervention may help limit the potential public health impact of ciguatera poisoning in industrial ship crewmembers and other fish-consuming communities in the future.