1. Department of Epidemiology and Preventive Medicine, School of Public Health, Faculty of Medicine Tel Aviv University Tel Aviv Israel
2. Central Virology Laboratory, Ministry of Health Chaim Sheba Medical Center Ramat Gan Israel
3. Pediatric Infectious Disease Unit The Edmond and Lily Safra Children's Hospital, Chaim Sheba Medical Centre Ramat Gan Israel
4. Faculty of Medicine Ariel University Ariel Israel
5. Faculty of Medicine Tel Aviv University Tel Aviv Israel