Print PageUntangling the ecological interactions happening inside hosts is critical for predicting the progression of natural infections and the effectiveness of drugs or vaccines. Though attempts to view microbial infections inside hosts as ecological communities exist, most human infectious disease researchers do not investigate ecological interactions within the body. To help explain the ecology inside hosts we present a conceptual framework that distils the important concepts and how they work together, thus providing to the non-ecologist, infectious disease specialist a take home message that they can use in their studies. The community ecology approach to in-host dynamics presented here uses food-web modules and life-history trade-offs to demonstrate the usefulness of viewing infections as food-webs inside the human body. By using a simple viral dynamics model we illustrate the value in finding the patterns of community assembly and the trade-offs that constrain the system in order to best understand how the system changes along a gradient of in-host environments.
Results/Conclusions
We find that in both chronic and acute infections, the outcome, such as persistence and strain dominance, depends on which in-host trade-offs are present, the traits of the strains involved and what type of host holds the infection. As a specific example, we will discuss the replication/clearance trade-off in Human Papillomavirus infections. We also demonstrate how parasite traits (such as defence strategies and resource use) fit within the module framework and can lead to longer persistence within a host. Finally, we walk through some simple alterations to routine study designs used by immunologists and epidemiologists that would help clarify the ecology happening inside a host. With the latter we hope that better predictions can be made as to how infectious diseases will evolve in response to new drugs or vaccines.
