1. Department of Medicine, Division of Infectious Diseases, Vanderbilt University School of Medicine, Nashville, Tennessee
2. Department of Biology, Texas A&M University, College Station, Texas
3. Department of Biostatistics, Vanderbilt University School of Medicine, Nashville, Tennessee
4. Department of Preventive Medicine and Biometrics
5. Department of Medicine, University of Colorado at Denver and Health Sciences Center, Denver, Colorado
6. Department of Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, Tennessee