Brucellosis in two seal pups
T. Jauniaux1,2, M. Didier1, D. Fretin3, J. Godfroid4, E. Laurent3, P. Michel3, M. Sarlet1, Van Gompel5, F. Coignoul1

1. Department of Pathology, Veterinary College, Sart Tilman Bat B43, 4000 Liege, Belgium
2. Royal Belgian Institute of Natural Sciences, MUMM, Gulledelle 100, 1200 Brussels, Belgium
3. Veterinary and Agrochemical Research Centre, Groeselenberg 99, 1180 Brussels, Belgium
4. Section for Arctic Veterinary Medicine, Department of Food Safety and Infection Biology, Norwegian School of Veterinary Science, Stakkevollveien 23, 9010 Tromsø, Norway
5. Sea Life Blankenberge, Koning Albert-I-laan 116, 8370 Blankenberge, Belgium Belgium

Brucella sp. infection has been documented in a wide range of marine mammal species inhabiting a large part of the world’s ocean but association between infection and lesion has only been established in cetaceans. A common seal Phoca vitulina and a grey seal Halichoerus grypus died suddenly in a rehabilitation center in Belgium. Post-mortem investigations revealed lesions such as lymph nodes petechiae or hyperplasia, pneumonia, nephritis, hepatitis and moderate meningitis. Immunohistochemistry investigations revealed positive staining for Brucella sp. in different tissues, including cerebral meninge and lung nematodes. Brucella pinnipedialis was isolated in different lymph nodes of both seals. In marine mammals, lesions associated with Brucella sp. infection have been reported in cetaceans only while for pinnipeds only serological evidences of Brucella sp. infection are described. Microscopic descriptions of lesions similar to those reported in the present study have been associated with Brucella sp. infections in cetaceans. In the present case, positive staining was observed in the areas of meningitis. Based on our observations, B. pinnipedialis can be considered as the cause of the meningitis in an acute stage. The presence of Brucella sp. in lungworms has been described previously in cetaceans and in pinnipeds. Lungworms larvae carrying Brucella sp. could be one of the routes of infection when eating intermediate host fish species. If such infection can be demonstrated, it will confirm the potential economic impact and public health implications as marine mammals Brucella sp. have been demonstrated being zoonotic. Then, all people handling wild or captive seals, alive or dead or samples collected from the animal should be aware of the zoonotic risk and take the necessary precaution.