1. Department of Virology, Haartman Institute, University of Helsinki, Helsinki, Finland.
2. Institute of Virology and Immunobiology, University of Würzburg, Würzburg, Germany.
3. Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, Stockholm, Sweden.
4. Department of Clinical Microbiology, Karolinska University Hospital, Stockholm, Sweden.
5. Department of Oncology and Pathology, Karolinska Institutet, Stockholm, Sweden.
6. Department of Pediatrics, Turku University Hospital, Turku, Finland.
7. Helsinki University Central Hospital Laboratory Division, Helsinki, Finland.