1. Infectious Disease Unit, 3rd Department of Pediatrics, Medical Faculty, Aristotle University School of Health Sciences Hippokration General Hospital Thessaloniki Greece
2. Pediatric Intensive Care Unit Hippokration General Hospital Thessaloniki Greece
3. Department of Hygiene and Epidemiology Aristotle University of Thessaloniki Thessaloniki Greece
4. Microbiology Department Hippokration General Hospital Thessaloniki Greece