1. Clinic for Gynecology and Obstetrics, Narodni Front, Kraljice Natalije 62, 11000 Belgrade, Serbia
2. Faculty of Medicine, University of Belgrade, Dr Subotica Starijeg 8, 11000 Belgrade, Serbia
3. Institute of Microbiology and Immunology, Department of Virology, Faculty of Medicine, University of Belgrade, Dr Subotića Starijeg Street, 11000 Belgrade, Serbia
4. Clinical Hospital Center, Dr Dragiša Mišović, Heroja Milana Tepica 1, 11000 Belgrade, Serbia