Brucella surveillance in marine mammalsstranded on the English Channel French coastline from 1995 to nowadays : epidemiological and pathological study

• Main Author: Balin, Allison
• Other Authors: Ecole Nationale Vétérinaire de Toulouse (ENVT), Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université de Toulouse (UT), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT), Hélène Daniels
• Format: Master Thesis
• Language: French
• Published: HAL CCSD 2016
• Subjects: Marine mammals; Immunochemistry; Epidemiology; Pathology; Zoonosis; Strandings; Mammifères marins; Zoonoses; Brucellose; PCR; Immunohistochimie; Epidémiologie; Pathologie; Zoonose; Echouages; Brucellosis; [SDV.BA.MVSA]Life Sciences [q-bio]/Animal biology/Veterinary medicine and animal Health; North East Atlantic
• Online Access: https://dumas.ccsd.cnrs.fr/dumas-04546151; https://dumas.ccsd.cnrs.fr/dumas-04546151/document; https://dumas.ccsd.cnrs.fr/dumas-04546151/file/Balin_17315.pdf

Brucellosis, an important zoonosis, can have serious consequences on human and animal health. Since the first cases of brucellosis detected in stranded cetaceans and seals in 1994, a large number of Brucella ceti and B. pinnipedialis have been reported, mostly in the North-East Atlantic coastline. Naturally acquired infection in humans by a marine Brucella have been described, suggesting the importance of studying the prevalence of marine brucellae in terms of public health. Actually, no data is available in France. The author try here to specify the causes of stranding of marine mammals on the English channel coastline, and, with these same animals, determine the prevalence and Brucella lesions. For this purpose, a statistical analysis about strandings between 1995 et 2014 has been done. It reveals that the main two causes of death identified were: traumatic associated with fishing net bycatch and infectious disease. However, new causes of mortality as severe emaciation and predation appear. Among these necropsied animals, 59 were investigated by real time polymerase chain reaction. The PCR was positive for 7 (11,86% (7/59)) of the 59 stranded animals (8,47% (5/59)). Under microscope, positive immunohistochemical staining was obtained in tissues, especially spleen and lungs. Finally, 2 marine mammals were false positive. Sequencing allows to confirm the infection by Brucella for 5 animals. Our study reveals the presence of Brucella in marine mammals along our coastline wich constitutes a biohazard for human health. As a first report in the world, a common dolphin meningoencephalitis was diagnosed. However, a critical analysis of our global results shows the failings on the specificity and sensibility of our lab methods. So, false positive and negative are no negligible. This observation highlights the need for additional research on causes of strandings and the relevance of Brucella for marine hosts and their environment for the impact of public health. La brucellose est une zoonose majeure pouvant entraîner ...