[1] Tel Aviv Univ, Sackler Fac Med, Sch Publ Hlth, Dept Epidemiol & Prevent Med, Tel Aviv, Israel
[2] Minist Hlth, Chaim Sheba Med Ctr, Cent Virol Lab, POB 5265601, Ramat Gan, Israel
[3] Chaim Sheba Med Ctr, Microbiol Lab, Ramat Gan, Israel
[4] Israel Minist Hlth, Israel Ctr Dis Control, Ramat Gan, Israel
[5] Ariel Univ, Dept Hlth Management, Ariel, Israel