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