1. Department of Ophthalmology; Barzilai Medical Center; Ashkelon Israel
2. Department of health science; Ben Gurion University; Be'er Sheva Israel
3. Department of Ophthalmology; Rambam Health Care Campus; Haifa Israel
4. Central Virology Laboratory; Ministry of Health; Chaim Sheba Medical Center; Ramat-Gan Israel
5. Department of Epidemiology and Preventive Medicine; School of Public Health; Sackler Faculty of Medicine; Tel-Aviv University; Tel-Aviv Israel