Institution: | 1. Department of Family and Community Medicine, College of Medicine, King Saud University, Riyadh, Saudi Arabia;2. Department of Microbiology, College of Medicine, King Saud University, Riyadh, Saudi Arabia;3. Department of Paediatrics, College of Medicine, King Saud University, Riyadh, Saudi Arabia;4. Prince Sattam Chair for Epidemiology and Public Health Research, Community Medicine Unit, College of Medicine, King Saud University, Riyadh, Saudi Arabia |