[1] Univ Lausanne Hosp, Infect Dis Serv, Dept Med, Lausanne, Switzerland
[2] Univ Lausanne, Lausanne, Switzerland
[3] Univ IUMSP, Univ Lausanne Hosp, Inst Social & Prevent Med, Lausanne, Switzerland
[4] Clin Moncucco, Lugano, Switzerland
[5] Univ Bern, Dept Clin Res, Bern, Switzerland
[6] Univ Basel, Dept Biomed, Basel, Switzerland
[7] Canton Hosp, Div Gastroenterol, St Gallen, Switzerland
[8] Pourtales Hosp, Neuchatel, Switzerland
[9] Univ Lausanne Hosp, Div Gastroenterol & Hepatol, Lausanne, Switzerland
[10] Univ Hosp, Div Clin Pathol, Geneva, Switzerland
[11] Univ Hosp, Div Gastroenterol & Hepatol, Geneva, Switzerland
[12] Univ Zurich Hosp, Div Gastroenterol & Hepatol, CH-8091 Zurich, Switzerland