1. University Medical Center Utrecht, Utrecht University; Julius Center for Health Sciences and Primary Care; HP: Str. 6.131 PO Box 85500 Utrecht Netherlands 3508 GA
2. University Groningen; Groningen Research Institute of Pharmacy; A. Deuslinglaan 1 9713 AV Groningen Netherlands
3. University College London; evidENT, Ear Institute; 330 Grays Inn Road London UK WC1X 8DA
4. University Medical Center Utrecht, Utrecht University; Julius Center for Health Sciences and Primary Care & Department of Otorhinolaryngology; Utrecht Netherlands
5. Wilhelmina Children's Hospital, University Medical Center Utrecht, Utrecht University; Department of Pediatric Immunology and Infectious Diseases; PO Box 85090 Utrecht Netherlands 3508 AB
6. The National Institute for Public Health and the Environment; Center for Infectious Diseases; Bilthoven Netherlands