Maria Rambla-Alegre, Vanessa del Río, Laia Reverté, Agathe Pirog, Òscar Palacios, Josep Caixach, Nathalie Arnich, Pablo de la Iglesia, Cintia Flores, Christian Ralijaona, Jean Turquet, Mònica Campàs, Hélène Magalon, Jorge Diogène, Iony Manitra Razanajatovo, Producció Animal, Aigües Marines i Continentals, Institute of Agrifood Research and Technology (IRTA), Institute of Environmental Assessment and Water Research (IDAEA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Institut Halieutique et des Sciences Marines, Université de Toliara, Ecologie marine tropicale dans les Océans Pacifique et Indien (ENTROPIE [Réunion]), Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Institut de Recherche pour le Développement (IRD), Agence nationale de sécurité sanitaire de l'alimentation, de l'environnement et du travail (ANSES), Hydrô Réunion, European Project: 311820,EC:FP7:KBBE,FP7-KBBE-2012-6-singlestage,ECSAFESEAFOOD(2013), European Commission, Institut de Recerca i Tecnologia Agroalimentàries = Institute of Agrifood Research and Technology (IRTA), and Institut de Recherche pour le Développement (IRD)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)
Severe food poisoning events after the consumption of sharks have been reported since the 1940s; however, there has been no clear understanding of their cause. Herein, we report for the first time the presence of ciguatoxins (CTXs) in sharks. The identification by mass spectrometry of CTXs, including two new analogues, in a bull shark (Carcharhinus leucas) that was consumed by humans, causing the poisoning and death of 11 people in Madagascar in 2013 is described. Typical neurotoxic ciguatera symptoms were recorded in patients, and toxicological assays on extracts of the shark demonstrated CTX-like activity. These results confirm this episode as a ciguatera poisoning event and expand the range of pelagic fish species that are involved in ciguatera in the Indian Ocean. Additionally, gambieric acid D, a molecule originally described in CTX-producing microalgae, was identified for the first time in fish. This finding can contribute to a better understanding of trophic relations within food webs. The present work confirms that consumption of sharks from the Indian Ocean should be considered a ciguatera risk, and actions should be taken to evaluate its magnitude and risk in order to manage shark fisheries. © 2017 The Author(s)., We kindly acknowledge Dr. Bernard Reche, the veterinarian in charge of the shark autopsies in La Réunion and who confirmed the viscera sample was stomach, and also Erwan Lagadec (CRVOI) for performing the DNA extraction. We also thank the World Health Organization (WHO) for facilitating the transfer of samples from Madagascar to Reunion Island. The authors acknowledge Dr. Chris Rodgers for his critical review of the manuscript and Dr. Melissa Dunkle for assistance with the English. The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007–2013) under the ECsafeSEAFOOD project (grant agreement no. 311820) and from CERCA/Generalitat de Catalunya program.