1. 1Department of Medical Microbiology, University Medical Center Utrecht, Utrecht, The Netherlands
2. 2Julius Centre for Health Sciences and Primary Care, University Medical Centre Utrecht, Utrecht, The Netherlands
3. 3Faculty of Medicine, Department of Biostatistics, University of Oslo, Oslo, Norway
4. 4Department of Mathematics and Statistics, University of Helsinki, Helsinki, Finland
5. 5Infection Genomics, Wellcome Trust Sanger Institute, Hinxton, UK