1. Department of Microbiology and Virology; Molecular Virology Unit; Fondazione IRCCS Policlinico San Matteo; Pavia Italy
2. Departments of Obstetrics and Gynecology; “V.Buzzi” Hospital, ICP; University of Milan; Milan Italy
3. Obstetric and Gynecology Unit; Fondazione IRCCS Ospedale Maggiore Policlinico di Milano; Milan Italy
4. Neonatology and Neonatal Intensive Care Unit; Fondazione IRCCS Policlinico San Matteo; Pavia Italy
5. Department of Clinical, Section of Microbiology, Surgical, Diagnostic, and Pediatric Sciences; University of Pavia; Pavia Italy