1. Department of Microbiology and Immunology, Montana State University, Bozeman, MT, USA
2. Center for the Ecology of Infectious Diseases, University of Georgia, Athens, GA, USA
3. Department of Biology, Indiana University, Bloomington, IN, USA
4. Institute of Biodiversity Animal Health and Comparative Medicine, University of Glasgow, Glasgow, UK
5. Department of Biology, Stanford University, Stanford, CA, USA