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Gael Kurath, Ph.D.

Viruses and infectious diseases are natural components of every ecosystem. In aquatic ecosystems of the Pacific Northwest infectious hematopoietic necrosis virus (IHNV) is a significant viral pathogen of many 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 also explore the biological basis of specialist (adapted to single host species) and generalist (adapted to multiple host species) viruses, using naturally evolved subgroups of IHNV. This has potential to explain changes in virus types and disease impacts 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.  Finally, we collaborate with other researchers to investigate the evolution of IHNV virulence after a historical host jump from sockeye salmon to farmed rainbow trout using a historical panel of over 60 IHNV isolates collected over the last 50 years. Long-term interests include understanding drivers of viral evolution and ecology, host and virus factors that define virus transmission and transmission models, 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

  • B.A. 1978. Microbiology, Miami University, Oxford, OH

Affiliations and Memberships*

  • University of Washington, affiliate faculty in Pathobiology with graduate faculty status. 1994 to Present (full professor since 2017).

  • University of Washington, affiliate faculty in the School of Aquatic and Fisheries Sciences with graduate faculty status (2007 to Present).

  • 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).

  • 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: Virology (1995-1998); Journal of Aquatic Animal Health (2002-2005); Diseases of Aquatic Organisms (2011-2015); 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); USDA-NIFA AFRI Diseases of Agricultural Animals program (2020).

  • American Fisheries Society, Fish Health Section, member since 1994, nominating/balloting committee member 2002-2003; chair 2004.

  • American Fisheries Society, Fish Health Section, elected vice-president 2006, executive committee 2006-2010, president 2008.

  • American Society for Virology member since 1983.

Honors and Awards

  • Special Achievement Award, American Fisheries, Society Fish Health Section, 1999

  • U.S. Department of the Interior Star Awards, 2000, 2003, 2004, 2008

  • Snieszko Distinguished Service Award, Fish Health Section, American Fisheries Society, 2020

Science and Products

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Filter Total Items: 146

Geography and host species shape the evolutionary dynamics of U genogroup infectious hematopoietic necrosis virus

Infectious hematopoietic necrosis virus (IHNV) is a negative-sense RNA virus that infects wild and cultured salmonids throughout the Pacific Coastal United States and Canada, from California to Alaska. Although infection of adult fish is usually asymptomatic, juvenile infections can result in high mortality events that impact salmon hatchery programs and commercial aquaculture. We used epidemiolog
Authors
Allison Black, Rachel Breyta, Trevor Bedford, Gael Kurath
By
Ecosystems Mission Area, Western Fisheries Research Center, Fish Health Program (FHP)

Spatial and temporal heterogeneity of infectious hematopoietic necrosis virus in Pacific Northwest salmonids

The aquatic rhaboviral pathogen infectious hematopoietic necrosis virus (IHNV) causes acute disease in juvenile fish of a number of populations of Pacific salmonid species. Heavily managed in both marine and freshwater environments, these fish species are cultured during the juvenile stage in freshwater conservation hatcheries, where IHNV is one of the top three infectious diseases that cause seri
Authors
Rachel Breyta, Allison Black, John Kaufman, Gael Kurath
By
Ecosystems Mission Area, Biological Threats and Invasive Species Research Program, Species Management Research Program, Western Fisheries Research Center, Fish Health Program (FHP)

Evolution of viral virulence: empirical studies

The concept of virulence as a pathogen trait that can evolve in response to selection has led to a large body of virulence evolution theory developed in the 1980-1990s. Various aspects of this theory predict increased or decreased virulence in response to a complex array of selection pressures including mode of transmission, changes in host, mixed infection, vector-borne transmission, environmenta
Authors
Gael Kurath, Andrew R. Wargo
By
Ecosystems Mission Area, Biological Threats and Invasive Species Research Program, Species Management Research Program, Western Fisheries Research Center, Fish Health Program (FHP)

Atlantic salmon, Salmo salar L. are broadly susceptible to isolates representing the North American genogroups of infectious hematopoietic necrosis virus

Beginning in 1992, three epidemic waves of infectious hematopoietic necrosis, often with high mortality, occurred in farmed Atlantic salmon Salmo salar L. on the west coast of North America. We compared the virulence of eleven strains of infectious hematopoietic necrosis virus (IHNV), representing the U, M and L genogroups, in experimental challenges of juvenile Atlantic salmon in freshwater. All
Authors
Gael Kurath, James R. Winton, Ole B. Dale, Maureen K. Purcell, Knut Falk, Robert D. Busch
By
Ecosystems Mission Area, Western Fisheries Research Center, Fish Health Program (FHP)

Phylogenetic relationships of Iranian infectious hematopoietic necrosis virus of rainbow trout (Oncorhynchus mykiss) based on the glycoprotein gene

Infectious hematopoietic necrosis virus (IHNV), a member of family Rhabdoviridae and genus Novirhabdoviridae, causes a highly lethal disease of salmon and trout. In Iran IHNV was first detected in 2001 on farms rearing rainbow trout (Oncorhynchus mykiss). To evaluate the genetic relationships of IHNV from northern and western Iran, the sequences of a 651-nt region of the glycoprotein gene were det
Authors
Milad Adel, Alireza Babaalian Amiri, Maryam Dada, Gael Kurath, Bahram Laktarashi, Amrolah Ghajari, Rachel Breyta
By
Ecosystems Mission Area, Western Fisheries Research Center, Fish Health Program (FHP)

Successful mitigation of viral disease based on a delayed exposure rearing strategy at a large-scale steelhead trout conservation hatchery

In 2009, the largest steelhead trout conservation hatchery in the state of Idaho, Dworshak National Fish Hatchery (NFH), lost over 50% of the juvenile steelhead trout (Oncorhynchus mykiss) population being reared for release. The causative agent of this high mortality was the viral pathogen infectious hematopoietic necrosis virus (IHNV). This was neither the first nor the worst epidemic of IHNV to
Authors
R. Breyta, Corie Samson, Marilyn Blair, Allison Black, Gael Kurath
By
Ecosystems Mission Area, Biological Threats and Invasive Species Research Program, Western Fisheries Research Center, Fish Health Program (FHP)

Experimental infection of six North American fish species with the North Carolina strain of spring Viremia of Carp Virus

Spring viremia of carp virus (SVCV) is a rhabdoviral pathogen associated with disease outbreaks in cultured and wild fish worldwide. Common carp (Cyprinus carpio carp), and koi (C. carpio koi) suffer the highest mortalities from SVCV infections, while other cyprinid fish species have varying susceptibility. Although salmonid fish typically are considered refractory to infection by SVCV, there have
Authors
Eveline J. Emmenegger, George E. Sanders, Carla M. Conway, Fred P. Binkowski, James R. Winton, Gael Kurath
By
Ecosystems Mission Area, Western Fisheries Research Center, Fish Health Program (FHP)

Differential susceptibility in steelhead trout populations to an emergent MD strain of infectious hematopoietic necrosis virus

A significant emergence of trout-adapted MD subgroup infectious hematopoietic necrosis virus (IHNV) began in the coastal region of Washington State, USA, in 2007. This emergence event lasted until 2011 and caused both asymptomatic adult fish infection and symptomatic epidemic disease and mortality in juvenile fish. Incidence of virus during this emergence demonstrated a heterogeneous distribution
Authors
R. Breyta, Amelia Jones, Gael Kurath
By
Ecosystems Mission Area, Western Fisheries Research Center, Fish Health Program (FHP)

In vivo and in vitro phenotypic differences between Great Lakes VHSV genotype IVb isolates with sequence types vcG001 and vcG002

Viral hemorrhagic septicemia virus (VHSV) is an aquatic rhabdovirus first recognized in farmed rainbow trout in Denmark. In the past decade, a new genotype of this virus, IVb was discovered in the Laurentian Great Lakes basin and has caused several massive die-offs in some of the 28 species of susceptible North American freshwater fishes. Since its colonization of the Great Lakes, several closely
Authors
Sierra M. Imanse, Emily R. Cornwell, Rodman G. Getchell, Gael Kurath, Paul R. Bowser
By
Ecosystems Mission Area, Western Fisheries Research Center, Fish Health Program (FHP)

Viral fitness does not correlate with three genotype displacement events involving infectious hematopoietic necrosis virus

Viral genotype displacement events are characterized by the replacement of a previously dominant virus genotype by a novel genotype of the same virus species in a given geographic region. We examine here the fitness of three pairs of infectious hematopoietic necrosis virus (IHNV) genotypes involved in three major genotype displacement events in Washington state over the last 30 years to determine
Authors
Alison M. Kell, Andrew R. Wargo, Gael Kurath
By
Ecosystems Mission Area, Western Fisheries Research Center, Fish Health Program (FHP)

A missing dimension in measures of vaccination impacts

Immunological protection, acquired from either natural infection or vaccination, varies among hosts, reflecting underlying biological variation and affecting population-level protection. Owing to the nature of resistance mechanisms, distributions of susceptibility and protection entangle with pathogen dose in a way that can be decoupled by adequately representing the dose dimension. Any infectious
Authors
M. Gabriela M. Gomes, Andrew Wargo, Marc Lipsitch, Gael Kurath, Carlota Rebelo, Graham F. Medley, Antonio Coutinho
By
Ecosystems Mission Area, Western Fisheries Research Center, Fish Health Program (FHP)

Molecular epidemiology and evolution of fish Novirhabdoviruses

The genus Novirhabdoviridae contains several of the important rhabdoviruses that infect fish hosts. There are four established virus species: Infectious hematopoietic necrosis virus (IHNV), Viral hemorrhagic septicemia virus (VHSV), Hirame rhabdovirus(HIRRV), and Snakehead rhabdovirus (SHRV). Viruses of these species vary in host and geographic range, and they have all been studied at the molecula
Authors
Gael Kurath
By
Ecosystems Mission Area, Western Fisheries Research Center, Fish Health Program (FHP)

Non-USGS Publications**

Kurath, G., and C. Robaglia. 1995. Genetic variation and evolution of satellite viruses and satellite RNAs. Pages 385-403 in A. Gibbs, C. Calisher, and F. Garcia-Arenal (eds.), Molecular Basis of Virus Evolution. Cambridge Press, Cambridge, U.K.
Kurath, G., and J.A. Dodds. 1995. Mutation analyses of molecularly cloned satellite tobacco mosaic virus during serial passage in plants: evidence for hotspots of genetic change. RNA 1: 491-500.
Kurath, G., and J.A. Dodds. 1994. Satellite tobacco mosaic virus sequence variants with only five nucleotide differences can interfere with each other in a cross protection-like phenomenon in plants. Virology 202(2): 1065-1069. DOI: https://doi.org/10.1006/viro.1994.1441.
Rodriguez-Alvarado, G., G. Kurath, and J.A. Dodds. 1994. Symptom modification by satellite tobacco mosaic virus in pepper types and cultivars infected with helper tobamoviruses. Phytopathology 84(6): 617-621. DOI: 10.1094/Phyto-84-617.
Kurath, G., M.E. C. Rey, and J.A. Dodds. 1993. Tobamovirus helper specificity of satellite tobacco mosaic virus involves a domain near the 5' end of the satellite genome. Journal of General Virology 74(7): 1233-1243. DOI: 10.1099/0022-1317-74-7-1233.
Kurath, G., M.E. C. Rey, and J.A. Dodds. 1992. Analysis of genetic heterogeneity within the type strain of satellite tobacco mosaic virus reveals several variants and a strong bias for G to A substitution mutations. Virology 189(1): 233-244. DOI: https://doi.org/10.1016/0042-6822(92)90699-P.
Kurath, G., and P. Palukaitis. 1990. Serial passage of infectious transcripts of a cucumber mosaic virus satellite RNA clone results in sequence heterogeneity. Virology 176(1): 8-15. DOI: https://doi.org/10.1016/0042-6822(90)90224-F.
Kurath, G., and P. Palukaitis. 1989. RNA sequence heterogeneity in natural populations of three satellite RNAs of cucumber mosaic virus. Virology 173(1): 231-240. DOI: https://doi.org/10.1016/0042-6822(89)90239-0.
Kurath, G., and P. Palukaitis. 1987. Biological activity of T7 transcripts of a prototype clone and a sequence variant clone of a satellite RNA of cucumber mosaic virus. Virology 159(2):199-208. DOI: https://doi.org/10.1016/0042-6822(87)90456-9.
Kurath, G., and J.C. Leong. 1985. Characterization of IHN virus mRNA species reveals a non-virion rhabdovirus protein. Journal of Virology 53(2):462-468.
Kurath, G., K.G. Ahern, G.D. Pearson, and J.C. Leong. 1985. Molecular cloning of six mRNA species of IHNV, a fish rhabdovirus: Gene order determined by R-loop mapping. Journal of Virology 53(2): 469-476.
Kurath, G., and R.Y. Morita. 1983. Some physiological studies on starvation survival of a marine Pseudomonas sp. Applied and Environmental Microbiology 45(4):1206-1211.

**Disclaimer: The views expressed in Non-USGS publications are those of the author and do not represent the views of the USGS, Department of the Interior, or the U.S. Government.

Science and Products

*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