1. Department of Clinical Sciences ‘L. Sacco’ Hospital, Section of Infectious Diseases and Immunopathology, University of Milan, Milan, Italy.
2. Department of Clinical Sciences ‘L. Sacco’ Hospital, Section of Microbiology, University of Milan, Milan, Italy.
3. 1st Infectious Diseases Clinic, ‘L. Sacco’ Hospital, Milan, Italy.
4. 2nd Infectious Diseases Clinic, ‘L. Sacco’ Hospital, Milan, Italy.
5. Epidemiology Unit, Department of Infectious, Parasite and Immune-Mediated Diseases, Italian Institute of Health, Rome, Italy.