10.5061/DRYAD.FFBG79CR5
Hall, Emily
0000-0002-2815-6651
Vanderbilt University
Brunner, Jesse
Washington State University
Hutzenbiler, Brandon
Washington State University
Crespi, Erica
Washington State University
Data from: Salinity stress increases the severity of ranavirus epidemics
in amphibian populations
Dryad
dataset
2020
Disease susceptibility
glucocorticoid
road ecology
wildlife disease
mass mortality event
Sigma Xi
https://ror.org/04nmj5x57
Grants in Aid of Research
Environmental Protection Agency
https://ror.org/03tns0030
EPA STAR 91767901
Washington State University
https://ror.org/05dk0ce17
Undergraduate Research Minigrant
Division of Environmental Biology
https://ror.org/03g87he71
1139199
2020-08-08T00:00:00Z
2020-08-08T00:00:00Z
en
https://doi.org/10.1098/rspb.2020.0062
93810 bytes
3
CC0 1.0 Universal (CC0 1.0) Public Domain Dedication
The stress-induced susceptibility hypothesis, which predicts chronic
stress weakens immune defenses, was proposed to explain increasing
infectious disease-related mass mortality and population declines.
Previous work characterized wetland salinization as a chronic stressor to
larval amphibian populations. Thus, we combined field observations with
experimental exposures quantifying epidemiological parameters to test the
role of salinity stress in the occurrence of ranavirus-associated mass
mortality events. Despite ubiquitous pathogen presence (94%), populations
exposed to salt runoff had slightly more frequent ranavirus related mass
mortality events, more lethal infections, and 117-times greater pathogen
environmental DNA. Experimental exposure to chronic elevated salinity
(0.8-1.6 g/L Cl-) reduced tolerance to infection, causing greater
mortality at lower doses. We found a strong negative relationship between
splenocyte proliferation and corticosterone in ranavirus-infected larvae
at a moderate elevation of salinity, supporting glucocorticoid-medicated
immunosuppression, but not at high salinity. Salinity alone reduced
proliferation further at similar corticosterone levels and infection
intensities. Finally, larvae raised in elevated salinity had 10-times more
intense infections and shed 5-times as much virus with similar viral decay
rates, suggesting increased transmission. Our findings illustrate how a
small change in habitat quality leads to more lethal infections and
potentially greater transmission efficiency, increasing the severity of
ranavirus epidemics.