1. Hospital for Infectious and Tropical Diseases, Clinical Centre of Serbia, Faculty of Medicine, University of Belgrade, Belgrade, Serbia
2. Institute of Pathology, Faculty of Medicine, University of Belgrade, Belgrade, Serbia
3. Institute of Epidemiology, Faculty of Medicine, University of Belgrade, Belgrade, Serbia
4. Institute of Medical Statistics and Informatics, Faculty of Medicine, University of Belgrade, Belgrade, Serbia
5. Virology Laboratory, Microbiology Department, Clinical Center of Serbia, Belgrade, Serbia