1. National Institute of Public Health - National Centre for Surveillance and Control of Communicable Diseases, Bucharest, Romania
2. Cantacuzino National Institute for Research and Development in Microbiology and Immunology, Bucharest, Romania
3. Institute of Public Health ‘Carlos III’, Madrid, Spain
4. National Institute of Public Health - Regional Centre of Public Health, Cluj, Romania
5. Robert Koch Institute, Berlin, Germany