1. Departments of Virology
2. Department of Clinical Chemistry, and Transfusion Medicine, Sahlgrenska University Hospital, Göteborg
3. Bacteriology, Swedish Institute for Infectious Disease Control, Solna
4. Hospital Infection Control Unit, Clinical Microbiology and Immunology
5. Department of Medicine, University of Lund, Lund
6. Division of Molecular Virology, Medical Faculty, University of Linköping, 581 85 Linköping, Sweden