1. Department of Epidemiology 1, Carol Davila University of Medicine and Pharmacy, 050474 Bucharest, Romania
2. Emergency Clinical Hospital for Children “Grigore Alexandrescu”, 011743 Bucharest, Romania
3. National Institute for Infectious Diseases “Prof. Dr. Matei Balș”, 021105 Bucharest, Romania
4. Department of Infectious Diseases 1, Carol Davila University of Medicine and Pharmacy, 020021 Bucharest, Romania
5. Department of Infectious Diseases 3, Carol Davila University of Medicine and Pharmacy, 020021 Bucharest, Romania