1. Department of Infectious Diseases, Örebro University Hospital, Örebro, Sweden
2. Department of Epidemiology, Swedish Institute for Infectious Disease Control, Solna, Sweden
3. Health Academy, Örebro University, Örebro, Sweden
4. European Centre for Disease Prevention and Control (ECDC), Stockholm, Sweden
5. Department of Medical Epidemiology and Biostatistics, Karolinska Institute, Stockholm, Sweden