Empirical evidence that metabolic theory describes the temperature dependency of within-host parasite dynamics

Abstract

The complexity of host–parasite interactions makes it difficult to predict how host–parasite systems will respond to climate change. In particular, host and parasite traits such as survival and virulence may have distinct temperature dependencies that must be integrated into models of disease dynamics. Using experimental data from Daphnia magna and a microsporidian parasite, we fitted a mechanistic model of the within-host parasite population dynamics. Model parameters comprising host aging and mortality, as well as parasite growth, virulence, and equilibrium abundance, were specified by relationships arising from the metabolic theory of ecology. The model effectively predicts host survival, parasite growth, and the cost of infection across temperature while using less than half the parameters compared to modeling temperatures discretely. Our results serve as a proof of concept that linking simple metabolic models with a mechanistic host–parasite framework can be used to predict temperature responses of parasite population dynamics at the within-host level.

Thermal biology of mosquito‐borne disease

“…• How can trait-based model predictions best be combined with observed dynamics of human cases to infer and predict the role of temperature in disease dynamics? 2013; Moln ar et al 2013;Kirk et al 2018Kirk et al , 2019. Whether these canonical values from metabolic theory apply to the traits of mosquitoes and pathogens that drive vector-borne disease transmission is unknown (Moln ar et al 2013(Moln ar et al , 2017.…”

Season affects strength and direction of the interactive impacts of ocean warming and biotic stress in a coastal seaweed ecosystem

“…By now, significant progress toward more realistic assessments has been achieved in multifactorial (several drivers) and multivariate (several responses) long‐term mesocosm studies (Sommer ; Jokiel et al ; Nagelkerken and Connell ; Riebesell and Gattuso ; Boyd et al ). Several studies show the capacity of biotic interactions—or the shift of such—to modulate or even mask the direct impact at the organism level of global‐change‐driven abiotic environmental pressures, for instance, for parasite‐host interactions (e.g., Kirk et al ), pathogen‐host interaction (e.g., Kiesecker and Blaustein ; Campbell et al ), epibiont‐host interaction (e.g., Werner et al ; Takolander et al ), competition, and predation (e.g., Alsterberg et al ; Falkenberg et al ; Goldenberg et al ; Provost et al ). The amplification or buffering of environmental impacts by biotic interactions should be particularly pronounced where foundational, that is, habitat‐forming, species are involved (Doney et al ).…”

Temperature dependence of parasitic infection and gut bacterial communities in bumble bees

“…One context in which the effect of temperature on species interactions has been repeatedly demonstrated to reflect the predictions of metabolic theory is that of host-parasite interactions (Raffel et al, 2013;Kirk et al, 2018;Cohen et al, 2019). Metabolic theory predicts that the success of parasites at any given temperature reflects the relative performance of hosts and parasites at that temperature, rather than the absolute performance of either in isolation (Cohen et al, 2017).…”

“…Metabolic theory predicts that the success of parasites at any given temperature reflects the relative performance of hosts and parasites at that temperature, rather than the absolute performance of either in isolation (Cohen et al, 2017). As a result, the temperature dependence of parasite growth may differ for parasites grown in cell cultures versus in live hosts (James, 2005;Cohen et al, 2017;Kirk et al, 2018).…”