1. From the Department of Pediatric Hematology-Oncology (T.A.O.), “Aghia Sophia” Children’s Hospital, Athens, Greece
2. Infectious Diseases Unit, Third Department of Pediatrics, Aristotle University of Thessaloniki, Hippokration General Hospital, Thessaloniki, Greece
3. Department of Microbiology, “Aghia Sophia” Children’s Hospital, Athens, Greece
4. Department of Pathology, “Aghia Sophia” Children’s Hospital, Athens, Greece.