[1] Univ Basel, Inst Med Microbiol, Dept Biomed, CH-4003 Basel, Switzerland
[2] Helsinki Univ Hosp, Transplant Unit, Res Lab, Transplantat & Liver Surg Clin, FI-00029 Helsinki, Hus, Finland
[3] Helsinki Univ Hosp, Div Nephrol, Dept Med, FI-00029 Helsinki, Hus, Finland
[4] Univ Helsinki, FI-00029 Helsinki, Hus, Finland
[5] Helsinki Univ Hosp, Dept Virol, FI-00029 Helsinki, Hus, Finland
[6] Univ Basel Hosp, Dept Med, CH-4031 Basel, Switzerland
[7] Univ Basel Hosp, Dept Internal Med Infect Dis & Hosp Epidemiol, CH-4031 Basel, Switzerland