[1] Hellen Ctr Dis Control & Prevent, Dept Intervent Hlth Care Facil, Athens, Greece
[2] Aristotle Univ Sch Med, Papageorgiou Hosp, Neonatal Intens Care Unit, Thessaloniki, Greece
[3] Hellen Ctr Dis Control & Prevent, Cent Publ Hlth Lab, Athens, Greece
[4] Aristotle Univ Sch Med, Papageorgiou Hosp, Dept Internal Med 3, Thessaloniki, Greece
[5] Aristotle Univ Sch Med, Hippokrat Hosp, Dept Paediat 3, Thessaloniki, Greece