META-ANALYSIS
We conducted a systematic review and meta-analysis to evaluate the impacts of three broad types of environmental stressors on disease dynamics. Our meta-analyses focused on two specific questions: Q1) are stressor fitness effects more severe for infected vs. uninfected hosts? and Q2) is infectivity more susceptible to environmental stress than host fitness traits? To address these questions with data from primary studies, we used infection intensity and prevalence as proxies for infectivity and survivorship and fecundity as proxies of host fitness.