1. Department of Family and Community Medicine, King Abdulaziz Medical City, National Guard Health Affairs, Riyadh, Saudi Arabia
2. Department of Pathology and Laboratory Medicine, King Abdulaziz Medical City, National Guard Health Affairs, Riyadh, Saudi Arabia
3. Department of Pediatrics Infectious Diseases, King Abdulaziz Medical City, National Guard Health Affairs, Riyadh, Saudi Arabia
4. BESC, Research Centre, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia