1. Department of Pediatrics, Rady Children’s Hospital, University of California, San Diego, California;
2. Department of Medicine, Boston Children’s Hospital, Harvard Medical School, Boston, Massachusetts;
3. Department of Pediatrics, Section of Emergency Medicine, Texas Children’s Hospital, Baylor College of Medicine, Houston, Texas;
4. Department of Pediatrics, Children’s Mercy Hospital, Kansas City, Missouri;
5. Departments of Molecular Virology and Microbiology, and Pediatrics, Baylor College of Medicine, Houston, Texas; and
6. Department of Emergency Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts