1. a Depatrment of Infectious Diseases , Catholic University of Rome , Italy
2. b International Agency for Research on Cancer , IARC , Lyon , France
3. c Obstetrics and Gynecology Clinic, S Paolo Hospital , University of Milan
4. d Obstetrics and Gynecology Clinic, L Sacco Hospital , University of Milan
5. e Institute of Tropical and Infectious Diseases, L Sacco Hospital , University of Milan
6. f Clinic of Infectious Diseases , University of Modena
7. g II Department of Infectious Diseases , L Sacco Hospital , Milan
8. h National Institute of Infectious Diseases , IRCCS L Spallanzani, Rome , Italy