DAO 55:211-220 (2003)  -  doi:10.3354/dao055211

Host and geographic range extensions of the North American strain of viral hemorrhagic septicemia virus

R. P. Hedrick1,*, W. N. Batts2, S. Yun1, G. S. Traxler3, J. Kaufman4, J. R. Winton2

1Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, California 95616, USA
2Western Fisheries Research Center, 6505 NE 65th Street, Seattle, Washington 98115, USA
3Pacific Biological Station, Department of Fisheries and Oceans, Nanaimo, British Columbia V9T 6N7, Canada
4Oregon Department of Fish and Wildlife, Department of Microbiology, Oregon State University, Corvallis, Oregon 97331, USA

ABSTRACT: Viral hemorrhagic septicemia virus (VHSV) was isolated from populations of Pacific sardine Sardinops sagax from the coastal waters of Vancouver Island, British Columbia, Canada, and central and southern California, USA. The virus was also isolated from Pacific mackerel Scomber japonicus in southern California, from eulachon or smelt Thaleichthys pacificus, and surf smelt Hypomesus pretiosus pretiosus from Oregon, USA. Mortality and skin lesions typical of viral hemorrhagic septicemia in other marine fish species were observed among sardine in Canada and in a few surf smelt from Oregon, but the remaining isolates of VHSV were obtained from healthy appearing fish. The prevalence of VHSV among groups of apparently healthy sardine, mackerel and smelt ranged from 4 to 8% in California and Oregon. A greater prevalence of infection (58%) occurred in groups of sardine sampled in Canada that sustained a naturally occurring epidemic during 1998-99. A captive group of surf smelt in Oregon exhibited an 81% prevalence of infection with clinical signs in only a few fish. The new isolates were confirmed as North American VHSV and were closely related based on comparisons of the partial nucleotide sequence of the glycoprotein (G) gene. The VHSV isolates from sardine in Canada and California were the most closely related, differing from isolates obtained from other marine fish species and salmonids in British Columbia, Canada, Alaska and Washington, USA. These new virus isolations extend both the known hosts (sardine, mackerel and 2 species of smelt) and geographic range (Oregon and California, USA) of VHSV.


KEY WORDS: Pilchard · Sardine · VHSV · G-gene · Glycoprotein · Rhabdovirus


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