[1] Univ Basel Hosp, Div Infect Dis & Hosp Epidemiol, CH-4031 Basel, Switzerland
[2] Univ Med Ctr Freiburg, Dept Environm Hlth Sci, Div Infect Control & Hosp Epidemiol, Freiburg, Germany
[3] Univ Basel Hosp, Div Haematol, CH-4031 Basel, Switzerland
[4] Univ Med Ctr Freiburg, Ctr Clin Studies, Freiburg, Germany
[5] Univ Med Ctr Freiburg, Dept Internal Med Haematol Oncol 1, Freiburg, Germany
[6] Univ Basel Hosp, Microbiol Lab, CH-4031 Basel, Switzerland