Maddalena Peghin1,2, Hans H Hirsch3,4,5. 1. Infectious and Tropical Diseases Unit, Department of Medicine and Surgery, University of Insubria-ASST-Sette Laghi, Varese, Italy. 2. Infectious Diseases Division, Department of Medicine, University of Udine and Azienda Sanitaria Universitaria Friuli Centrale, Udine, Italy. 3. Division of Infectious Diseases and Hospital Epidemiology, University Hospital Basel, University of Basel, Basel, Switzerland. 4. Clinical Virology, Laboratory Medicine, University Hospital Basel, Basel, Switzerland. 5. Transplantation and Clinical Virology, Department of Biomedicine, University of Basel, Basel, Switzerland.