EN
Derzsy's disease occurring in geese is caused by a virus from the Parvoviridae family called the Derzsy's disease virus or goose parvovirus. For thirty years Derzsy's disease has been observed in Poland and currently it is the cause of large economic losses. The main objective of the study was come up with the molecular characteristics of Derzsy's disease virus strains isolated from field cases. The samples were taken from 65 goose flocks. The geese, 1.5-6-weeks-of-age, were suspected of being affected with Derzsy's disease. Seven viral isolates were isolated from visceral organs of the geese and on the basis of cytopathic changes in goose embryo fibroblasts culture and pathological changes in goose embryos were classified as Derzsy's disease virus strains. One band of 806 bp size, which is characteristic of Derzsy's disease virus, was demonstrated in PCR. On the basis of phylogenetic analysis, the strains were classified as goose parvovirus. The strains were qualified to two phylogenetic groups: vaccine and low pathogenicity strains and field strains. The calculated similarity between the studied strains ranged from 92.3% to 100% and between European strains from 91.3% to 99.5%. On the basis of the authors' research it can be claimed that Polish Derzsy's disease strains differ slightly from each other but all of the strains have a common European origin.