title: Impact of environmental stressors on the dynamics of disease transmission.
abstract: Infectious disease within outmigrant juvenile salmon in the Columbia River Basin is modulated, in part, by abiotic stressors that influence host-susceptibility. Through the application of a dose-structured population dynamic model, we show that chemical (both in the river and in the estuary) and in-river (e.g., dams and/or predation) stressors influence host-susceptibility, increasing the mean force of infection (defined as the per capita acquisition rate of infection) by a factor of 2.2 and 1.6, respectively. Using Listonella anguillarum as a model pathogen, nonchemical in-river and chemical stressors contribute equally to a cumulative incidence of delayed disease-induced mortalities in Chinook salmon that range from 3% to 18% for estuary residence times of 30-120 days, respectively. Mitigation of environmental stressors that increase host-susceptibility could represent a significant component in future management strategies to recover listed stocks.
authors.affiliation: Department of Civil and Environmental Engineering, University of California at Davis, 1 Shields Avenue, Davis, California 95616, USA. fjloge@ucdavis.edu
authors.forename: Frank J
authors.initials: FJ
authors.lastname: Loge
authors.forename: Mary R
authors.initials: MR
authors.lastname: Arkoosh
authors.forename: Timothy R
authors.initials: TR
authors.lastname: Ginn
authors.forename: Lyndal L
authors.initials: LL
authors.lastname: Johnson
authors.forename: Tracy K
authors.initials: TK
authors.lastname: Collier
mesh_terms: D000818:Animals; D002138:Calibration; D003141:Communicable Diseases / Q000635:transmission*; D003247:Conservation of Natural Resources; D004198:Disease Susceptibility / Q000382:microbiology*; D004305:Dose-Response Relationship, Drug; D017753:Ecosystem; D004777:Environment; D004784:Environmental Monitoring / Q000379:methods*; D005393:Fish Diseases / Q000382:microbiology*; D009922:Oregon; D012306:Risk; D012474:Salmon; D013997:Time Factors; D014737:Vibrionaceae / Q000378:metabolism*; D014861:Washington