1. Department of Emergency Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts;
2. Department of Pediatrics, University of Louisville, Louisville, Kentucky;
3. Department of Medicine, Boston Children’s Hospital, Harvard Medical School, Boston, Massachusetts;
4. Department of Pediatrics, Santa Clara Valley Medical Center, San Jose, California; and
5. Departments of Molecular Virology and Microbiology, and Pediatrics, Baylor College of Medicine, Houston, Texas