1. Department of Microbiology and Immunology, McGill University, Montreal, Canada
2. The University of Texas Health Science Center at San Antonio, Department of Medicine, Division of Infectious Diseases San Antonio, Texas
3. Division of Infectious Diseases, Department of Medicine, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, California
4. The David Geffen School of Medicine at UCLA, Los Angeles, California