Emerging tropical diseases in Australia. part 2. Ciguatera fish poisoning

Abstract

Ciguatera poisoning is a food-borne neuro-intoxication caused by consumption of finfish that have accumulated ciguatoxins in their tissues. Ciguatera is a distressing and sometimes disabling condition that presents with a self-limiting though occasionally severe gastro-intestinal illness, progressing to a suite of aberrant sensory symptoms. Recovery can take from days to years; second and subsequent attacks may manifest in a more severe illness. Ciguatera remains largely a pan-tropical disease, although tourism and export fish markets facilitate increased presentation in temperate latitudes. While ciguatera poisoning in the South Pacific was recognised and eloquently described by seafarers in the 18th Century, it remains a public-health challenge in the 21st Century because there is neither a confirmatory diagnostic test nor a reliable, low-cost screening method to ascertain the safety of suspect fish prior to consumption. A specific antidote is not available, so treatment is largely supportive. The most promising pharmacotherapy of recent decades, intravenous mannitol, has experienced a relative decline in acceptance after a randomized, double-blind trial failed to confirm its efficacy. Some questions remain unanswered, however, and the use of mannitol for the treatment of acute ciguatera poisoning arguably deserves revisiting. The immunotoxicology of ciguatera is poorly understood, and some aspects of the epidemiology and symptomatology of ciguatera warrant further enquiry.