[1] Univ Barcelona, Fac Pharm, Dept Microbiol & Parasitol, E-08007 Barcelona, Spain
[2] Hosp Univ La Fe, Dept Gastroenterol, Valencia, Spain
[3] Univ Oviedo, Hosp Cent Asturias, Digest Tract Dept, E-33080 Oviedo, Spain
[4] Complejo Hosp Univ Albacete, Dept Gastroenterol, Albacete, Spain
[5] Hosp Univ Ramon y Cajal, Dept Gastroenterol, Madrid, Spain
[6] Hosp Navarra, Serv Digest Tract, Pamplona, Spain
[7] Univ Hosp Reina Sofia, Dept Gastroenterol & Hepatol, Cordoba, Spain
[8] Hosp San Jorge, Gastroenterol & Hepatol, Huesca, Spain
[9] Hosp Univ Puerta del Mar, Dept Digest Tract, Cadiz, Spain
[10] Hosp Clin Univ San Carlos, Dept Digest Tract, Madrid, Spain
[11] Hosp Donostia, Dept Gastroenterol, San Sebastian, Spain
[12] Univ Basque Country, UPV EHU, Inst Biodonostia, E-48080 Bilbao, Spain
[13] Ctr Invest Biomed Red Enfermedades Hepat & Digest, Madrid, Spain
[14] Hosp Univ Princesa, Inst Invest Sanitaria Princesa IIS IP, Madrid, Spain
[15] Univ Autonoma Barcelona, Inst Univ Parc Tauli, Hosp Sabadell, Unitat Epidemiol & Avaluacio,Fundacio Parc Tauli, Sabadell, Spain
[16] Corp Sanitaria Univ Parc Tauli, Dept Gastroenterol, Sabadell, Barcelona, Spain
[17] Univ Autonoma Barcelona, Dept Med, E-08193 Barcelona, Spain