Viruses and infectious diseases are natural components of every ecosystem. In aquatic ecosystems infectious hematopoietic necrosis virus (IHNV) is the most significant viral pathogen of many Pacific salmonid fish populations. Studies of IHNV molecular biology, pathogenesis, field ecology, and evolution contribute to understanding and management of viral disease in salmon and trout.
Research Interests:
Our research involves viral diseases in finfish, with an emphasis on the rhabdovirus IHNV in Pacific salmon and trout of Pacific Northwest ecosystems. We conduct landscape-scale genetic typing of IHNV as it occurs across Western North America and use phylogenetic analyses and molecular epidemiology to identify patterns of virus occurrence, transmission, and disease impacts across large geographic regions, and over many years. This has revealed divergence of IHNV into three major genetic groups (U, M, or L) with distinct host specificities and geographic ranges in North America. There is also clear evidence for viral host jumps, displacement events, and evolution of both specialist and generalist virus lineages. Potential drivers of these evolutionary events are tested in controlled wet laboratory challenge studies in salmonid fish, providing sound scientific data on the biological basis of patterns observed in the field. In a recent project we demonstrated evolution of increasing virulence as a driver of viral genotype displacements in steelhead trout of the Columbia River Basin, and worked with collaborators to develop the first landscape-scale transmission model for IHNV. We are currently embarking on a new project to explore the biological basis of why viruses evolve to be specialists (adapted to single host species), versus generalists (adapted to use multiple host species). This has potential to explain changes in virus types and disease impacts recently observed in the Columbia River Basin, and it also serves as a tractable research model for empirical testing of predictions of basic specialist-generalist theory for pathogens. Long-term interests include understanding drivers of viral evolution and ecology, transmission patterns among wild and cultured fish, and how human activities can be modified to avoid unintended disease consequences.
Professional Experience
1992 to Present - Research Microbiologist, U.S. Geological Survey, Western Fisheries Research Center, Seattle, WA
1989 - 1992 - Postdoctoral researcher, Plant Virology, University of California, Riverside, CA
1985 - 1988 - Postdoctoral researcher, Plant Virology, Cornell University, Ithaca, NY
Education and Certifications
Ph.D. 1985. Virology, Oregon State University, Corvallis, OR
M.S. 1980. Marine Microbiology, Oregon State University, Corvallis, OR
Affiliations and Memberships*
University of Washington, affiliate faculty with graduate faculty status in Pathobiology (1994 to Present) and School of Aquatic and Fishery Sciences (2007 to Present).
University of Washington, affiliate faculty and graduate faculty status School of Aquatic and Fisheries Sciences (2007 to Present).
University of Washington, currently affiliate full professor.
International Committee on Taxonomy of Viruses, member of study groups Rhabdovirus family (1997 to Present), Paramyxovirus Family (2008 to present), and Mononegavirales Super-family (2008 to Present).
Scientific Journal Editorial Board or co-editor: Virology (1995-1998).
Scientific Journal Editorial Board or co-editor: Journal of Aquatic Animal Health (2002-2005).
Scientific Journal Editorial Board or co-editor: Veterinary Research (2011).
Scientific Journal Editorial Board or co-editor: Diseases of Aquatic Organisms (2011-2015).
Scientific Journal Editorial Board or co-editor: Journal of General Virology (2011-2016).
Ad hoc reviewer for numerous journals.
Grant review panel member or panel chair: USDA Biotechnology Risk Assessment (1996, 1997); USDA NRI Virology (1999, 2000).
American Fisheries Society, Fish Health Section
American Society for Virology
Honors and Awards
American Fisheries Society, Fish health Section, elected nominating and balloting committee member 2002, committee chair 2004; elected section vice-president 2006, section president 2008.
Science and Products
Investigation and Disease Prevention of Spring Viremia of Carp Virus (SVCV)
Reference Laboratory Service - FHP
Emerging Viruses - FHP
Viral Hemorrhagic Septicemia (VHS) - FHP
Infectious Hematopoietic Necrosis (IHN) - FHP
Spring Viremia of Carp (SVC) - FHP
Yellow Perch (Perca flavescens) - FHP
Koi (Cyprinus carpio koi) - FHP
Science and Products
- Science
Investigation and Disease Prevention of Spring Viremia of Carp Virus (SVCV)
There has been long history of disease outbreaks and economic losses in wild and farmed carp species due to SVCV. Formerly thought to be restricted to Europe and Asia, SVCV was detected for the first time in North America from diseased koi at a North Carolina fish farm in 2002, and there were extensive eradication efforts with 135,000 fish euthanized in addition to the ~15,000 that died from the...Reference Laboratory Service - FHP
The Fish Health Section provides reference laboratory services to identify viral pathogens submitted by staff from the Northwest Indian Fisheries Commission (NWIFC) fish health laboratory.Emerging Viruses - FHP
Fish Diseases - Emerging VirusesViral Hemorrhagic Septicemia (VHS) - FHP
Fish Diseases - Viral Hemorrhagic Septicemia (VHS)Infectious Hematopoietic Necrosis (IHN) - FHP
Fish Diseases - Infectious Hematopoietic Necrosis (IHN)Spring Viremia of Carp (SVC) - FHP
Fish Diseases - Spring Viremia of Carp (SVC)Yellow Perch (Perca flavescens) - FHP
Species Studied - Yellow Perch (Perca flavescens)Koi (Cyprinus carpio koi) - FHP
Species Studied - Koi (Cyprinus carpio koi) - Data
- Publications
- Web Tools
- Software
- News
- Multimedia
*Disclaimer: Listing outside positions with professional scientific organizations on this Staff Profile are for informational purposes only and do not constitute an endorsement of those professional scientific organizations or their activities by the USGS, Department of the Interior, or U.S. Government