1. Centers for Pediatrics and Adolescent Medicine and
2. Chronic Immunodeficiency, University Medical Center, Freiburg, Freiburg, Germany;
3. Respiratory and Vaccine Preventable Bacteria Reference Unit, Microbiology Services Division, Health Protection Agency, Colindale, London, United Kingdom; and
4. Clinic and Policlinic for Pediatrics and Adolescent Medicine, University Hospital Carl Gustav Carus, Technical University Dresden, Dresden, Germany