The case of viral haemorrhagic septicaemia and infectious hematopoietic necrosis in rainbow trout fly - Introduction of RT-PCR technique for the diagnosis of these viruses in Poland

In rainbow trout sac fry the mixed infection of VHSV and IHNV has been desc ribed. The relationship between the presence of these viruses and fry morta lity was confirmed, as evidenced by the high virus titer (up to 8,6x10(6) T CID50/ml.) in fish tissues and organs, as well as the lack of other potenti al etiological agents. The presence of rhabdoviruses in sac fry was proved with TEM. Among the typical virus particles, some aberrant-elongated or fil amentous and bifurcate forms were also detected. The presence of the viruse s was proved using BF-2 and EPC cell lines previously inoculated with the f ield material, and for its identification the RT-PCR technique was applied for the first time in Poland, both in standard and multiplex modification. VHS virus was also identified with ELISA test and IHN virus with seroneutra lisation test. The source of VHS and IHN infection in sac fry has been disc ussed.