1. Department of Pathology, Stanford University School of Medicine , Stanford, California , USA
2. Division of Infectious Diseases and Geographic Medicine, Department of Medicine, Stanford University School of Medicine , Stanford, California , USA
3. Division of Infectious Diseases, Department of Pediatrics, Stanford University School of Medicine , Stanford, California , USA
4. Clinical Virology Laboratory, Stanford Health Care , Stanford, California , USA
5. Department of Microbiology and Immunology , Stanford, California , USA
6. Clinical Microbiology Laboratory, Stanford Health Care , Stanford, California , USA