1. Faculty of Medicine, Carol Davila University of Medicine and Pharmacy, 050474 Bucharest, Romania
2. National Institute of Public Health, National Centre for Communicable Diseases Surveillance and Control, 050463 Bucharest, Romania
3. Department of Viral Emerging Diseases, Stefan. S. Nicolau Institute of Virology, 030304 Bucharest, Romania
4. Romanian Academy, 010071 Bucharest, Romania