Parasite responses to resource provisioning can be altered by within-host co-infection interactions

Anthropogenic changes to the environment significantly impact wildlife infectious diseases by modifying food resources and impacting host-parasite interactions through changes in host demography, behaviour, and immune defences. Supplemental resource provisioning has been found to both enhance and mitigate parasite transmission; however, the role of co-infecting parasites in mediating these effects remains understudied. We developed a mathematical model to explore these dynamics, motivated by the empirical system of wood mice (Apodemus sylvaticus) infected with the nematode Heligmosomoides polygyrus, which suppresses co-infections by the apicomplexan microparasite Eimeria hungaryensis. Our model shows that the effects of resource provisioning on parasite epidemiology can be mediated, and potentially reversed, by within-host co-infection interactions, through effects on host-parasite contact rates and host susceptibility. Provisioning may elevate microparasite prevalence by reducing nemat..., , , # Parasite responses to resource provisioning can be altered by within-host co-infection interactions

**Short Summary**\
This repository contains code for a mathematical model exploring how supplemental food provisioning influences parasite dynamics in wildlife, specifically focusing on co-infections in wood mice (*Apodemus sylvaticus*). The model examines interactions between the nematode *Heligmosomoides polygyrus* and the microparasite *Eimeria hungaryensis*, showing that resource provisioning can either increase or decrease parasite prevalence depending on how it alters host contact rates, susceptibility, and within-host co-infection interactions. The code provides a framework for studying how environmental changes shape multi-parasite epidemiology.

[https://doi.org/10.5061/dryad.msbcc2g72](https://doi.org/10.5061/dryad.msbcc2g72)

## Description of the data and file structure

### Code and Package Versions

* **Manual version number**: `v1.0 (initial release)`
* **R version**: 4....,