Resources and within-host disease dynamics

What are the consequences of within-host resource distribution for individual health and parasite loads? How should host defense strategies vary with resource availability?  To address such questions, I utilize laboratory experiments, outdoor mesocoms, and field studies. Additionally, in collaboration with Andrea Graham, Anieke van Leeuwen, and Clay Cressler, we are developing a dynamic energy budget mode of within-host resource dynamics.

Resources and co-infection

The effects of environmental and within-host resources on co-infected individuals and interactions among parasites is largely unknown. I study these interactions, and their implications for individual health and disease transmission in laboratory, field, and human studies. I collaborate with researchers at the University of Georgia, Princeton University, Leiden University Medical Center, Stanford University, and Virginia Tech for these projects.

Host responses and fitness costs of infection

Host defense strategies (both behavioral and immunological) can mediate the individual and population-level consequences of infection. In collaboration with Vanessa Ezenwa and Anna Jolles, I combined the power of a removal experiment with a longitudinal, species-level infection study to quantify the costs of worm infection and the contributions of differential host responses to those costs in a wild population of African buffalo. I was also able to verify the accuracy of a sublethal, combined molecular-morphological approach to assess parasite communities in the wild.

Experimental parasite community assembly

Extending community assembly theory to communities of co-infecting parasites, I used a gastrointestinal nematode removal experiment in free-ranging African buffalo to examine the community assembly patterns and processes.

Macroecology of Infectious Diseases

Macroecology image.png
Stephens et al. 2016. Ecology Letters, 19:1159-1171. 

In collaboration with Macroecology of Infectious Diseases RCN, I study large-scale patterns of host-parasite interactions. My work investigates global patterns of helminth infection and reverse zoonoses, the spillover of disease from humans to non-human animals.

Pesticides and infection

I investigated the effects of pesticide exposure on growth, development, survival, and susceptibility to parasite infection in larval amphibians in collaboration with Bill Hopkins and Lisa Belden,