1. Department of Sociology, Sofia University “St. Kliment Ohridski”, Sofia, Bulgaria
2. Department of Epidemiology, National Center of Infectious and Parasitic Diseases, Sofia, Bulgaria
3. Department of Epidemiology and Disaster Medicine, Medical University Plovdiv, Plovdiv, Bulgaria
4. Department of Social Medicine and Public Health, Medical University Plovdiv, Plovdiv, Bulgaria
5. Communities and Identities Department, Bulgarian Academy of Sciences, Sofia, Bulgaria
6. Department of Virology, National Center for Infectious and Parasitic Diseases, Sofia, Bulgaria