1. Department of Molecular Epidemiology and Biotechnology, Swedish Institute for Infectious Disease Control, Solna, Sweden and Microbiology and Tumor Biology Center, Karolinska Intitutet, Sweden
2. Smittskyddsenheten, Karolinska Hospital, Stockholm, Sweden
3. Department of Molecular Epidemiology and Biotechnology, Swedish Institute for Infectious Disease Control, Solna, Sweden