1. Third Department of Paediatrics, National and Kapodistrian University of Athens, Attikon General Hospital
2. Department of Clinical Microbiology, National and Kapodistrian Universi\ty of Athens, Attikon General Hospital
3. Department of Microbiology, School of Medicine, National and Kapodistrian University of Athens
4. Laboratory of Clinical Virology, School of Medicine, University of Crete