1. Institute of Experimental Morphology, Pathology and Anthropology with Museum, Bulgarian Academy of Sciences, Acad. G. Bonchev Str ., Block 25, 1113 Sofia , Bulgaria
2. Institute of Parasitology, Slovak Academy of Sciences , 040 11 Košice , Hlinkova 3, Slovakia
3. Biomedical Research Centre, Institute of Virology, Slovak Academy of Sciences , Dúbravská cesta 9, 845 05 Bratislava , Slovakia
4. Department of Public Health and Infectious Diseases, Section of Parasitology, Sapienza University of Rome , Piazzale Aldo Moro 5, 00185 Rome , Italy
5. Southwest State Enterprise , 2700 Blagoevgrad , Zora 18 , Bulgaria