1 Pediatric and Infectious Diseases Unit, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy.
2 Research Unit in Congenital and Perinatal Infections, Division of Immunology and Infectious Diseases, Academic Department of Pediatrics (DPUO), Bambino Gesù Children's Hospital, IRCCS, Rome, Italy.
3 Pediatrics, University Department of Pediatrics, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy.
4 Unit of Clinical Epidemiology, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy.