1. Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, Davis, California.
2. California Department of Public Health, Viral and Rickettsial Disease Laboratory, Richmond, California.
3. California Department of Fish and Wildlife, Wildlife Investigations Lab, Rancho Cordova, California.
4. Department of Biology, New Mexico State University, Las Cruces, New Mexico.
5. Department of Psychology, University of California, Davis, Davis, California.