1. San Antonio Military Medical Center, Infectious Disease Service, San Antonio, Texas 78234
2. Department of Medicine, The University of Texas Health Science Center and Pharmacy Service, University Hospital, San Antonio, Texas 78229
3. Department of Microbiology and Immunology, The University of Texas Health Science Center, San Antonio, Texas 78229
4. Department of Pathology, The University of Texas Health Science Center, San Antonio, Texas 78229