1. Baranya County Institute of State Public Health Service, Pécs, HungaryUniversity of Pécs, Hungary
2. Baranya County Institute of State Public Health Service, Pécs, Hungary
3. University of Pécs, Hungary
4. ”St. Laszlo” Central Hospital for Infectious Diseases, Budapest, Hungary
5. University of Bari, Bari, Italy
6. Centers for Disease Control and Prevention, Atlanta, Georgia, USA