[1] UNIV HOSP GENEVA,DIV GASTROENTEROL,GENEVA,SWITZERLAND
[2] UNIV HOSP GENEVA,DIV CLIN PATHOL,GENEVA,SWITZERLAND
[3] UNIV HOSP GENEVA,DIV DIGEST SURG,GENEVA,SWITZERLAND
[4] UNIV HOSP GENEVA,VIROL LAB,GENEVA,SWITZERLAND
[5] ABBOTT,WIESBADEN,GERMANY
[6] ROCHE,BASEL,SWITZERLAND