Hyperbilirubinemia of Coho Salmon Oncorhynchus kisutch Infected with Erythrocytic Inclusion Body Syndrome (EIBS) Virus

Anemia caused by hemolysis occurred in coho salmon Oncorhynchus kisutch infected with the erythrocytic inclusion body syndrome (EIBS) virus.Bilirubin levels were significantly higher in the plasma of diseased fish than in healthy fish.Hyperbilirubinemia occurred in fish infected with EIBS virus.Erythrocytic superoxide dismutase activities were induced in the diseased fish.The liver bilirubin level of diseased fish was much higher than that of control fish, while the total bile acid level in the plasma of diseased fish was much higher than in the control.The plasma astaxanthin level in the diseased fish was lower than that in the control, whereas plasma vitamin A levels of both were similar.These results suggest that excretion of bile acid decreased in the diseased fish.The accumulation of bilirubin in the liver and the disfunctional bile acid excretion indicate that secretory disorder of bilirubin occurred in the diseased fish and was one of the causes of hyperbilirubinemia observed in coho salmon infected with EIBS virus.