Pathogenicity of viral hemorrhagic septicemia virus (VHSV) isolated from olive flounder Paralichthys olivaceus to masu salmon Oncorhynchus masou

Abstract

The pathogenicity of viral hemorrhagic septicemia virus (VHSV) from olive flounder Paralichthys olivaceus was investigated with masu salmon Oncorhynchus masou fry. The cumulative mortality of fish challenged with FYeosu05 isolate at 10 6.5 TCID50/fish was 60%. No mortality was observed in fish challenged with the isolates at 10 5.5 TCID50/fish and in mock-challenged fish. The affected fish showed darkening of the body, expanded abdomen, pale gills and enlarged spleen. VHSV from 10 6.3 to 10 7.8 TCID50/g-tissue was re-isolated from the dead fish. These results suggest that the VHSV from olive flounder is pathogenic to masu salmon fry, although with low virulence.

Antiviral Efficacy of an Aquatic Disinfectant Tablet Composed of Calcium Hypochlorite Against Viral Hemorrhagic Septicemia Virus

“…3) Also, VHSV in Far Eastern Asia could be an indigenous virus in Korean and Japanese coastal area. 6) In Korea, VHSV was not detected before 2000, but in 2001, VHSV infection occurred in juveniles of farmed olive flounder (Paralichthys olivaceus) at Pohang, in eastern Korea. 7) Thereafter, more widespread VHS outbreaks occurred in Korean olive flounder farms, 8) with VHS becoming an endemic problem in the Korean aquaculture industry.…”