[1] Odense Univ Hosp, Dept Infect Dis, DK-5000 Odense, Denmark
[2] Gothenburg Univ, Dept Infect Dis, Gothenburg, Sweden
[3] Aarhus Univ, Dept Infect Dis, Aarhus, Denmark
[4] Univ Helsinki, Dept Gastroenterol, Helsinki, Finland
[5] Univ Bergen, Dept Infect Dis, Bergen, Norway
[6] Uppsala Univ, Dept Infect Dis, Uppsala, Sweden