1. South Texas Veterans Health Care System
2. Department of Medicine, Division of Infectious Diseases, University of Texas Health Science Center at San Antonio, San Antonio, Texas
3. Valley Coastal Bend Veterans Health Care System
4. Department of Epidemiology and Biostatistics, University of Texas Health Science Center at San Antonio, San Antonio, Texas
5. University of Texas Southwestern Medical Center, Dallas, Texas
6. Central Texas Veterans Health Care System
7. Department of Pathology, University of Texas Health Science Center at San Antonio, San Antonio, Texas
8. Parkland Health and Hospital System, Dallas, Texas