1. Department of Internal Medicine I, Medical Faculty, University Hospital Bonn, University of Bonn , Bonn , Germany
2. German Center for Infection Research, Thematical Translation Units HIV , Cologne/Bonn , Germany
3. Institute of Virology, University Hospital, University of Bonn , Bonn , Germany
4. Institute of Medical Microbiology, University Hospital Essen, University of Duisburg-Essen , Essen , Germany
5. Institute for Experimental Hematology and Transfusion Medicine, Medical Faculty, University Hospital Bonn, University of Bonn , Bonn , Germany