1. Department of Infectious Diseases School of Medical Sciences Faculty of Medicine and Health Örebro University Örebro Sweden
2. Clinical Epidemiology and Biostatistics School of Medical Sciences Örebro University Örebro Sweden
3. Clinical Epidemiology Division Karolinska Institutet Stockholm Sweden
4. Department of Epidemiology and Public Health University College London London UK
5. Department of Infectious Diseases Karolinska University Hospital Stockholm Sweden
6. Department of Medicine Huddinge Karolinska Institutet Stockholm Sweden