1. Institute of Molecular Virology, ZMBE, Westfaelische-Wilhelms-University, Von Esmarch-Str. 56, D-48149 Muenster, Germany
2. Robert-Koch-Institute, P15, Nordufer 20, D-13353 Berlin, Germany
3. Institute of Medical Virology, Justus-Liebig-University, Frankfurter Strasse 107, D-35392 Giessen, Germany
4. Friedrich-Loeffler-Institute, Paul-Ehrlich-Strasse 28, D-72076 Tübingen, Germany
5. Klinik fuer Gastroenterologie, Hepatologie und Infektiologie, Heinrich-Heine-University, D-40225 Duesseldorf, Germany