1 Tel Aviv District Health Office, Ministry of Health, Tel Aviv, Israel.
2 Division of Epidemiology, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel.
3 Infectious Diseases Unit, Wolfson Medical Center, Holon, Israel.
4 Central Virology Laboratory, Ministry of Health, Chaim Sheba Medical Center, Ramat-Gan, Israel.
5 Central Virology Laboratory, Ministry of Health, Chaim Sheba Medical Center, Ramat-Gan, Israel; Department of Epidemiology and Preventive Medicine, School of Public Health, Sackler Faculty of Medicine, Tel-Aviv University, Tel-Aviv, Israel.
6 Central Virology Laboratory, Ministry of Health, Chaim Sheba Medical Center, Ramat-Gan, Israel. Electronic address: [email protected].