Host-pathogen interactions under pressure: a review and meta-analysis of stress-mediated effects on disease dynamics
Amanda Vicente-Santos1*, Beatriz Willink2,3,4, Kacy Nowak5, David J. Civitello1,6, and Thomas R. Gillespie1,5,7*
1Population Biology, Ecology, and Evolution Program, Emory University, Atlanta, GA 30322, USA
2Department of Zoology, Stockholm University, Stockholm 106-91, Sweden
3Department of Biological Sciences, National University of Singapore, Singapore 117558, Singapore
4School of Biology, University of Costa Rica, San José 11501-2060, Costa Rica
5Department of Environmental Health, Rollins School of Public Health, Emory University, Atlanta, GA 30322, USA
6 Department of Biology, Emory University, Atlanta, GA 30322, USA
7Department of Environmental Sciences, Emory University, Atlanta, GA 30322, USA
*Correspondence: Amanda Vicente-Santos. Sutton Hall 107, Biology Department, University of Oklahoma, Norman, OK 73019, USA amanda.vicente@ou.edu Tel. +1(404) 276-9990; and
Thomas R. Gillespie. 400 Dowman Drive, Suite E510, Department of Environmental Sciences, Emory University, Atlanta, GA 30322, USA thomas.gillespie@emory.edu Tel: +1(404) 727-7926
Running title: Stress-mediated effects on disease dynamics
Keywords : resource limitation, environmental stress, pollution, survival, fecundity, infectivity, epidemiological models
Email addresses:amanda.vicente@ou.edu, beatriz.willink@zoologi.su.se, kkacy.nnowak@gmail.com, david.james.civitello@emory.edu, thomas.gillespie@emory.edu
Statement of authorship: AVS conceived the study. AVS, BW, DJC, and TRG designed the project and plans for data collection. AVS, BW, and KN collected data. AVS, BW, KN, and DJC analyzed the data. AVS, BW, and DJC designed figures and tables with inputs from all authors. AVS and DJC conceived and created the models. AVS, BW, and TRG drafted the manuscript. All authors revised and edited the manuscript for intellectual content.
Data accessibility statement: Data is available from the Dryad Digital Repository (doi:10.5061/dryad.zw3r228cd).
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Abstract: Human activities have increased the intensity and frequency of natural stressors and created novel stressors, altering host-pathogen interactions, and changing the risk of emerging infectious diseases. Despite the ubiquity of such anthropogenic impacts, predicting the directionality of outcomes has proven challenging. Here, we conduct a review and meta-analysis to determine the primary mechanisms through which stressors affect host-pathogen interactions and to evaluate the impacts stress has on host fitness (survival and fecundity) and pathogen infectivity (prevalence and intensity). We assessed 891 effect sizes from 71 host species (representing seven taxonomic groups) and 78 parasite taxa from 98 studies. We found that infected and uninfected hosts had similar sensitivity to stressors and that responses varied according to stressor type. Specifically, limited resources compromised host fecundity and decreased pathogen intensity, while abiotic environmental stressors (e.g., temperature and salinity) decreased host survivorship and increased pathogen intensity, and pollution increased mortality but decreased pathogen prevalence. We then used our meta-analysis results to develop Susceptible-Infected theoretical models to illustrate scenarios where infection rates are expected to increase or decrease in response to resource limitation or environmental stress gradients. Our results carry implications for conservation and disease emergence and reveal areas for future work.