1. Department of Epidemiology, Swedish Institute for Infectious Disease Control, Solna, Sweden.
2. Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Solna, Sweden.
3. Department of Bacteriology, Swedish Institute for Infectious Disease Control, Solna, Sweden.
4. Microbiology and Tumour Biology Center, Karolinska Institutet, Solna, Sweden.
5. Department of Medical Microbiology, Malmö University Hospital, Malmö, Sweden.
6. Department of Medical Microbiology, Lund University Hospital, Lund, Sweden.
7. Regional Department of Communicable Disease Control in Skåne, Malmö, Sweden.