[1] Univ Zurich Hosp, Div Infect Dis, CH-8091 Zurich, Switzerland
[2] Univ Zurich Hosp, Hosp Epidemiol, Dept Visceral & Transplantat Surg, Clin Gastroenterol & Hepatol,Clin Nephrol, CH-8091 Zurich, Switzerland
[3] Univ Hosp, Inselspital, Div Infect Dis Clin Pharmacol Visceral & Transpla, Bern, Switzerland
[4] Univ Hosp Geneva, Div Infect Dis Gastroenterol & Surg, Geneva, Switzerland
[5] Univ Lausanne Hosp, Dept Surg, Transplantat Ctr, Div Infect Dis, Lausanne, Switzerland
[6] La Source Hosp, Lausanne, Switzerland
[7] Univ Basel Hosp, Div Infect Dis, Basel, Switzerland