1. Department of Pediatrics, Division of Infectious Diseases, Duke University School of Medicine , Durham, North Carolina , USA
2. Duke Clinical Research Institute, School of Medicine, Duke University , Durham, North Carolina , USA
3. Department of Internal Medicine, University of Iowa , Iowa City, Iowa , USA
4. Department of Pediatrics, Division of Infectious Diseases, University of California at San Diego, La Jolla, California, USA and Rady Children’s Hospital San Diego , San Diego, California , USA
5. Department of Pediatrics, Division of Infectious Diseases, University of New Mexico School of Medicine , Albuquerque, New Mexico , USA