Emerging ciguatera fish poisoning in the Archipelago of Madeira (Portugal): epidemiology and clinical profile

The expansion of ciguatera fish poisoning (CFP) into non-endemic regions, such as the Madeira Archipelago in the northeastern Atlantic Ocean, has raised significant concerns for public health and marine resource management. Since the first reported case in 2008, at least 55 cases of CFP have occurred in Madeira, despite the implementation of fishing bans targeting the most high-risk species. This study describes the epidemiological patterns and clinical manifestations of CFP in the region from 2007 to 2024, highlighting that not only apex predatory fish are associated with poisoning events. Cutaneous or mucocutaneous issues (itching), prominently pruritus, were reported in all cases. Gastrointestinal and neurological symptoms, especially diarrhoea, abdominal pain, paraesthesia-extremity and cold allodynia were among the very most frequent. On the other hand, cardiovascular manifestations were less common. The onset of the symptoms were generally reported within 24 h of food ingestion, and in some cases persited up to 6 months. Results of this study also indicate an urgent need to further improve the management and control of this illness from an environmental perspective, involving the fisheries industry and recreational fishers, as well as from the perspective of the regional authorities responsible for public health and medical response. • Tropical endemic ciguatera is now a threat in Madeira. • Gastrointestinal and neurological symptoms are frequent, cardiovascular are less common. • Symptoms may persist from 24 h to 6 months. • Not only top predators fish are associated with the food poisoning.