A Review of Seroepidemiology in Pinnipeds along the Coast of Hokkaido, Japan

Abstract

　In the past decades, some infectious diseases have caused several mass-mortalities in pinnipeds and given a huge threat on conservation of pinnipeds and marine ecosystem. Although such a mass-mortality event has not been observed on the coast of Japan, several serologic investigations have shown the specific antibodies against five pathogens; influenza virus, morbillivirus, Brucella, Toxoplasma gondii, and Neospora caninum, in pinnipeds along the coast of Hokkaido. In this article, we review these serologic studies together with the recent topics on these infectious diseases. Because the interspecies transmission of these pathogens occurs through contacts or food chain, it is necessary to examine a larger range of mammals and relating animals such as birds, food animals and parasites in the connecting area between land and sea. Recent climate change has a potential to change the habitant ranges and behaviors of wild mammals, and resultantly increase the risk of interspecies transmission of the pathogens. It is important to continue the monitoring not only in pinnipeds but also in the expanded range of animals in Hokkaido.