I am a quantitative biologist with special interests in the evolutionary ecology of host-pathogen interactions in aquatic systems. I use experimental and survey data to test alternative models describing the mechanisms of host-pathogen interactions at different levels, such as within and among hosts.
My research career started in fish biology, investigating ecological and evolutionary factors that lead to alternative reproductive phenotypes in Atlantic salmon. I then moved into the field of disease ecology where I further developed skills in quantitative biology, evolutionary ecology, and genomics. During my postdoc years, I conducted disease ecology research in several systems, including spongy moth-baculoviruses and fruit bats-paramyxoviruses. Since about 2018, I have been studying disease ecology in fish species of the Pacific Northwest, including salmonids and clupeids.
Professional Experience
Post-doc - The University of Chicago
Post-doc - Montana State University
Post-doc - The University of Alabama
Education and Certifications
BS - Monash University (Melbourne, Australia)
Ph.D. - Université Laval (Québec, Canada)
Affiliations and Memberships*
Ecological Society of America
Science and Products
Entry and spread of specialist and generalist infectious hematopoietic necrosis virus (IHNV) genotypes in Chinook salmon, steelhead and sockeye salmon
Infectious hematopoietic necrosis virus (IHNV) represents one of the most critical challenges for salmonids in the Pacific Northwest. There are three genogroups of IHNV, designated U, M, and L; the U is further delineated into two subgroups, UC and UP, and the M is further delineated into four subgroups (MA – MD). The UP, UC and MD subgroups co-occur in the Columbia River Basin where the host spec
Shed viral load and survival of spring-run and fall-run Columbia River Basin Chinook salmon exposed to 3 genogroups of infectious hematopoietic necrosis virus (IHNV)
This investigation sought to characterize the shedding of infectious hematopoietic necrosis virus (IHNV) in two populations of Columbia River Basin (CRB) Chinook salmon (Oncorhynchus tshawytscha). Juvenile spring- and fall-run Chinook salmon were exposed by immersion to each of three IHN virus strains from the UC, MD, and L subgroups, and then monitored for viral shedding from individual fish for
Survival and viral load of chinook salmon, sockeye salmon, and steelhead trout exposed to 4 genogroups of infectious hematopoietic necrosis virus (IHNV)
Theory of the evolution of pathogen specialization suggests that a specialist pathogen gains high fitness in one host, but this comes with fitness loss in other hosts. By contrast, a generalist pathogen does not achieve high fitness in any host, but gains ecological fitness by exploiting different hosts, and has higher fitness than specialists in non-specialized hosts. As a result, specialist path
Characteristics of a sea louse (Caligus clemensi) epizootic in wild Pacific herring (Clupea pallasii)
We characterized a natural sea louse epizootic of Caligus clemensi and the effects of parasitism on Pacific herring Clupea pallasii in Port Angeles Harbor, WA, USA. Infestation prevalence on newly metamorphosed age 0 Pacific herring reached 100% prevalence by mid-August. At this time, the mean louse intensity was 4.6 lice/fish, and a positive correlation occurred between louse intensity and herrin
Authors
David James Páez, Jacob L. Gregg, Ashley MacKenzie, Sophie Amanda Hall, Paul Hershberger
Coproduction and modeling spatial contact networks prevent bias about infectious hematopoietic necrosis virus transmission for Snake River Basin salmonids
Much remains unknown about variation in pathogen transmission across the geographic range of a free-ranging fish or animal species and about the influence of movement (associated with husbandry practices or animal behavior) on pathogen transmission. Salmonid hatcheries are an ideal system in which to study these processes. Salmonid hatcheries are managed for endangered species recovery, supplement
Authors
Jeffrey P. Mattheiss, Rachel Breyta, Gael Kurath, Shannon L. LaDeau, David James Páez, Paige F. B. Ferguson
Variation in within-host replication kinetics among virus genotypes provides evidence of specialist and generalist infection strategies across three salmonid host species
Theory of the evolution of pathogen specialization suggests that a specialist pathogen gains high fitness in one host, but this comes with fitness loss in other hosts. By contrast, a generalist pathogen does not achieve high fitness in any host, but gains ecological fitness by exploiting different hosts, and has higher fitness than specialists in nonspecialized hosts. As a result, specialist patho
Authors
David James Páez, Douglas G. McKenney, Maureen K. Purcell, Kerry A. Naish, Gael Kurath
Temperature variation and host immunity regulate viral persistence in a salmonid host
Environmental variation has important effects on host–pathogen interactions, affecting large-scale ecological processes such as the severity and frequency of epidemics. However, less is known about how the environment interacts with host immunity to modulate virus fitness within hosts. Here, we studied the interaction between host immune responses and water temperature on the long-term persistence
Authors
David J. Páez, Rachel L. Powers, Peng Jia, Natalia Ballesteros, Gael Kurath, Kerry A. Naish, Maureen K. Purcell
Infectious hematopoietic necrosis virus specialization in a multihost salmonid system
Many pathogens interact and evolve in communities where more than one host species is present, yet our understanding of host–pathogen specialization is mostly informed by laboratory studies with single species. Managing diseases in the wild, however, requires understanding how host–pathogen specialization affects hosts in diverse communities. Juvenile salmonid mortality in hatcheries caused by inf
Authors
David Paez, Shannon L. LaDeau, Rachel Breyta, Gael Kurath, Kerry A. Naish, Paige Ferguson
Science and Products
- Data
Entry and spread of specialist and generalist infectious hematopoietic necrosis virus (IHNV) genotypes in Chinook salmon, steelhead and sockeye salmon
Infectious hematopoietic necrosis virus (IHNV) represents one of the most critical challenges for salmonids in the Pacific Northwest. There are three genogroups of IHNV, designated U, M, and L; the U is further delineated into two subgroups, UC and UP, and the M is further delineated into four subgroups (MA – MD). The UP, UC and MD subgroups co-occur in the Columbia River Basin where the host specShed viral load and survival of spring-run and fall-run Columbia River Basin Chinook salmon exposed to 3 genogroups of infectious hematopoietic necrosis virus (IHNV)
This investigation sought to characterize the shedding of infectious hematopoietic necrosis virus (IHNV) in two populations of Columbia River Basin (CRB) Chinook salmon (Oncorhynchus tshawytscha). Juvenile spring- and fall-run Chinook salmon were exposed by immersion to each of three IHN virus strains from the UC, MD, and L subgroups, and then monitored for viral shedding from individual fish forSurvival and viral load of chinook salmon, sockeye salmon, and steelhead trout exposed to 4 genogroups of infectious hematopoietic necrosis virus (IHNV)
Theory of the evolution of pathogen specialization suggests that a specialist pathogen gains high fitness in one host, but this comes with fitness loss in other hosts. By contrast, a generalist pathogen does not achieve high fitness in any host, but gains ecological fitness by exploiting different hosts, and has higher fitness than specialists in non-specialized hosts. As a result, specialist path - Multimedia
- Publications
Characteristics of a sea louse (Caligus clemensi) epizootic in wild Pacific herring (Clupea pallasii)
We characterized a natural sea louse epizootic of Caligus clemensi and the effects of parasitism on Pacific herring Clupea pallasii in Port Angeles Harbor, WA, USA. Infestation prevalence on newly metamorphosed age 0 Pacific herring reached 100% prevalence by mid-August. At this time, the mean louse intensity was 4.6 lice/fish, and a positive correlation occurred between louse intensity and herrinAuthorsDavid James Páez, Jacob L. Gregg, Ashley MacKenzie, Sophie Amanda Hall, Paul HershbergerCoproduction and modeling spatial contact networks prevent bias about infectious hematopoietic necrosis virus transmission for Snake River Basin salmonids
Much remains unknown about variation in pathogen transmission across the geographic range of a free-ranging fish or animal species and about the influence of movement (associated with husbandry practices or animal behavior) on pathogen transmission. Salmonid hatcheries are an ideal system in which to study these processes. Salmonid hatcheries are managed for endangered species recovery, supplementAuthorsJeffrey P. Mattheiss, Rachel Breyta, Gael Kurath, Shannon L. LaDeau, David James Páez, Paige F. B. FergusonVariation in within-host replication kinetics among virus genotypes provides evidence of specialist and generalist infection strategies across three salmonid host species
Theory of the evolution of pathogen specialization suggests that a specialist pathogen gains high fitness in one host, but this comes with fitness loss in other hosts. By contrast, a generalist pathogen does not achieve high fitness in any host, but gains ecological fitness by exploiting different hosts, and has higher fitness than specialists in nonspecialized hosts. As a result, specialist pathoAuthorsDavid James Páez, Douglas G. McKenney, Maureen K. Purcell, Kerry A. Naish, Gael KurathTemperature variation and host immunity regulate viral persistence in a salmonid host
Environmental variation has important effects on host–pathogen interactions, affecting large-scale ecological processes such as the severity and frequency of epidemics. However, less is known about how the environment interacts with host immunity to modulate virus fitness within hosts. Here, we studied the interaction between host immune responses and water temperature on the long-term persistence
AuthorsDavid J. Páez, Rachel L. Powers, Peng Jia, Natalia Ballesteros, Gael Kurath, Kerry A. Naish, Maureen K. PurcellInfectious hematopoietic necrosis virus specialization in a multihost salmonid system
Many pathogens interact and evolve in communities where more than one host species is present, yet our understanding of host–pathogen specialization is mostly informed by laboratory studies with single species. Managing diseases in the wild, however, requires understanding how host–pathogen specialization affects hosts in diverse communities. Juvenile salmonid mortality in hatcheries caused by infAuthorsDavid Paez, Shannon L. LaDeau, Rachel Breyta, Gael Kurath, Kerry A. Naish, Paige Ferguson - News
*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