1. Section of Infectious Diseases, Medical Service, Oklahoma City VA Health Care System, Oklahoma City, Oklahoma, USA
2. Department of Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
3. Department of Pathology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
4. Department of Pathology, Oklahoma City VA Health Care System, Oklahoma City, Oklahoma, USA
5. Pharmacy Service, Oklahoma City VA Health Care System, Oklahoma City, Oklahoma, USA