[1] Univ Basel Hosp, Div Infect Dis & Hosp Epidemiol, CH-4031 Basel, Switzerland
[2] Univ Basel Hosp, Basel Inst Clin Epidemiol & Biostat, CH-4031 Basel, Switzerland
[3] Univ Hosp Bern, Dept Infect Dis, CH-3010 Bern, Switzerland
[4] Univ Bern, Bern, Switzerland
[5] Univ Zurich Hosp, Div Infect Dis & Hosp Epidemiol, CH-8091 Zurich, Switzerland
[6] Cantonal Hosp, Div Infect Dis & Hosp Epidemiol, St Gallen, Switzerland
[7] Univ Hosp, Div Infect Dis & Hosp Epidemiol, Geneva, Switzerland
[8] Univ Lausanne Hosp, Div Infect Dis & Hosp Epidemiol, Lausanne, Switzerland
[9] Cantonal Hosp, Div Infect Dis & Hosp Epidemiol, Lugano, Switzerland