1. Division of Infectious Diseases , Travel- and Tropical Medicine, , Kunibertskloster 11-13D-50668, Cologne , Germany
2. Clinic for Internal Medicine, St. Marien-Hospital , Travel- and Tropical Medicine, , Kunibertskloster 11-13D-50668, Cologne , Germany
3. Division of Infectious Diseases and Tropical Medicine, University Hospital, LMU Munich , Leopoldstraße 5 D - 80799, Munich , Germany
4. Institute for Medical Microbiology, Immunology and Parasitology, University Hospital Bonn , Venusberg - Campus 153127, Bonn , Germany
5. German Center for Infection Research (DZIF) , Partner Site Bonn-Cologne, Bonn , Germany
6. German Center for Infection Research (DZIF) , Partner Site Munich, Munich , Germany