Abstract
Indirect fluorescent antibody technique (IFAT) usinganti-NeVTA nucleocapsid rabbit serum was applied to rapid diagnosis of salmonid herpesvirus 2 (SH-2) infection in maricultured coho salmon, Oncorhynchus kisutch. Virus-specific fluorescence was seen in nuclei of the CHSE-214 cells infected with NeVTA and coho salmon herpesvirus isolant 9003 (CSH9003). This antiserum could be successfully used for detection of the virus from the liver, heart, spleen and kidney of diseased fish. With IFAT using frozen sections and smears of diseased coho salmon liver, the detecting ratio of the virus was over 90% and comparable to the ratio obtained by virus isolation. In the liver, stored at -18°C for 30 days, extreme loss of viral infectivity occurred and no virus was isolated from the liver stored for 200 days. On the other hand, virus-specific fluorescence could be observed without any decrease of intensity in the smeared samples prepared from the liver stored for 200 days. This method was proved to be a simple, rapid and reliable diagnostic method for SH-2 infection.
