[1] Univ Zurich, Univ Zurich Hosp, Dept Infect Dis, Zurich, Switzerland
[2] Univ Zurich, Hosp Epidemiol, Univ Hosp Zurich, Zurich, Switzerland
[3] Univ Basel, Univ Basel Hosp, Div Clin Epidemiol, Dept Clin Res, Basel, Switzerland
[4] Univ Bern, Univ Hosp Bern, Dept Infect Dis, Inselspital, Bern, Switzerland
[5] Univ Basel, Univ Basel Hosp, Div Infect Dis, Basel, Switzerland
[6] Univ Basel, Hosp Epidemiol, Univ Hosp Basel, Basel, Switzerland
[7] Univ Hosp Bern, Dept Infect Dis, Bern, Switzerland
[8] Cantonal Hosp St Gallen, Div Infect Dis, St Gallen, Switzerland
[9] Cantonal Hosp St Gallen, Hosp Epidemiol, St Gallen, Switzerland
[10] Univ Hosp Geneva, Div Infect Dis, Geneva, Switzerland
[11] Univ Basel, Univ Basel Hosp, Div Infect Dis, Basel, Switzerland
[12] Univ Basel, Univ Basel Hosp, Hosp Epidemiol, Basel, Switzerland
[13] Lausanne Univ Hosp, Div Infect Dis, Lausanne, Switzerland
[14] Ente Osped Cantonale Lugano, Div Infect Dis, Lugano, Switzerland