1. These authors contributed equally to the manuscript
2. Central Virology Laboratory, Public Health Services, Ministry of Health and Sheba Medical Center, Ramat-Gan, Israel
3. Tel Aviv District Health Office, Ministry of Health, Tel Aviv, Israel
4. District Health Office, Ministry of Health, Tiberias, Israel
5. School of Health Sciences, Ashkelon Academic College, Ashkelon, Israel
6. Division of Epidemiology, Ministry of Health, Jerusalem, Israel
7. Faculty of Medicine, Department of Epidemiology and Preventive Medicine, Tel-Aviv University, Tel Aviv, Israel