1. Departments of Medicine, University of California, San Diego School of Medicine, San Diego, California.
2. Departments of Pathology, University of California, San Diego School of Medicine, San Diego, California.
3. Departments of Microbiology, University of Texas Southwestern Medical Center, Dallas, Texas.
4. Departments of Medicine, University of Texas Southwestern Medical Center, Dallas, Texas.
5. VA Healthcare, San Diego, California.