[1] Univ Athens, Dept Pediat 1, Hematol Oncol Unit, Aghia Sophia Childrens Hosp, Athens 11527, Greece
[2] Univ Athens, Dept Pediat 1, Infect Dis Unit, Aghia Sophia Childrens Hosp, Athens 11527, Greece
[3] Univ Athens, Sch Med, Dept Microbiol, Aghia Sophia Childrens Hosp, Athens 11527, Greece