1. Department of Pathology Medical University of Vienna Vienna Austria
2. Department of Virology Medical University of Vienna Vienna Austria
3. University Clinic Eppendorf Hamburg Germany
4. Department of Gastroenterology, Hepatology and Endocrinology Medical School of Hanover Hanover Germany
5. Institute for Pathology Medical School of Hanover Hanover Germany
6. Institute of Pathology University Hospital Cologne Cologne Germany
7. Department of Gastroenterology Medical University of Vienna Vienna Austria