Acknowledgements
We are grateful to all participating children and their parents and for the help from all attending nurses and doctors in inclusion of patients. We thank Drs. R. Grotli and R. Bull at the Department of Radiology, Akershus University Hospital, for performing radiological examinations, Dr. I. Aaberge, A. Aase, T. K. Herstad, A. C. Kristoffersen and Dr. D. Vestrheim at the Norwegian Institute of Public Health for performing pneumococcal serological tests, and staff at the laboratories at Akershus University Hospital for performing all other tests.
Contributors’ statement
All authors provided substantial contributions to the study’s conception and design, and acquisition, analysis or interpretation of the data.
Drs. Berg, Inchley, Fjaerli and Nakstad executed the clinical part of the work.
Dr. Leegaard was responsible for the microbiological laboratory analyses.
Dr. Berg drafted the initial manuscript, and all other authors revised it critically for important intellectual content. All authors approved the final manuscript as submitted, and agreed to be accountable for all aspects of the work.
Disclosure statement
The authors have no conflicts of interest or financial relationships relevant to this article to disclose.
Funding information
The study was supported by research grants from Akershus University Hospital and South-Eastern Norway Regional Health Authority, and grants from the Grimsgaard Foundation and the Norwegian Organization for Surveillance of Antimicrobial Resistance.