1. Infectious Diseases Departments of University of Modena, Italy
2. ASST Grande Ospedale Metropolitano Niguarda, Milano, Italy
3. University of Bologna, Italy
4. Azienda Ospedaliera Universitaria Ospedali Riuniti, Ancona, Italy; and
5. Gastroenterology Department ASST Papa Giovanni XXIII, Bergamo, Italy