1. Second Department of Pediatrics, National and Kapodistrian University of Athens School of Medicine, Athens, Greece
2. First Department of Paediatrics, P and A Kyriakou Children's Hospital, Athens, Greece
3. Division of Infectious Diseases, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
4. National Reference Laboratory for Mycobacteria, Sotiria Chest Diseases Hospital, Athens, Greece
5. Division of Infectious Diseases, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA; Department of Pediatrics and Epidemiology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA