1. Virology Department, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran;
2. Department of Virology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran;
3. Department of Obstetrics and gynecology, Imam Khomeini Hospital, Tehran University of Medical Sciences, Tehran, Iran;
4. Department of Epidemiology and Biostatistics, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.