1. Veterans Affairs Medical Center, Minneapolis, Minnesota
2. Department of Medicine, University of Minnesota, Minneapolis, Minnesota
3. Department of Psychiatry, University of Minnesota, Minneapolis, Minnesota
4. Department of Clinical Microbiology, Health Sciences Centre, Winnipeg, Manitoba, Canada
5. Department of Medical Microbiology, Faculty of Medicine, University of Manitoba, Manitoba, Canada
6. Department of Medicine, Health Sciences Centre, Winnipeg, Manitoba, Canada