1. Hellenic Center for Disease Control & Prevention, Athens, Greece
2. European Programme in Intervention Epidemiology Training (EPIET), European Centre for Disease Prevention and Control (ECDC), Stockholm, Sweden
3. Hellenic National Blood Centre, Athens, Greece
4. Medical Faculty, University of Athens, Athens, Greece
5. Medical Faculty, University of Thessaloniki, Thessaloniki, Greece
6. Medical Faculty, University of Thessaly, Larisa, Greece