Authors
Gergana N. Sandeva
Department of Hygiene, Epidemiology and Infectious Diseases, Medical Faculty, Trakia University, Stara Zagora, Bulgaria
Rositsa P. Deliradeva
Department of Hygiene, Epidemiology and Infectious Diseases, Medical Faculty, Trakia University, Stara Zagora, Bulgaria
Pavlina L. Gidikova
Department of Hygiene, Epidemiology and Infectious Diseases, Medical Faculty, Trakia University, Stara Zagora, Bulgaria