Molecular Epidemiology Issues of BVDV Infection in the Eastern Ukraine

Abstract

Aim. This study was focused on (i) detection of specifi c BVDV-antibodies within selected cattle farms, (ii) identifi cation of persistently infected (PI) animals and (iii) genetic typing of selected BVDV isolates. Methods. RNA extraction, real-time polymerase chain reaction, ELISA technique, sequencing. Results. Specifi c BVDV- antibodies were detected in 713 of 1,059 analyzed samples (67.3 per cent). This number is in agreement with fi ndings in many cattle herds around the world. However, the number of positive samples differed in the herds. While 57 samples out of 283 (20.1 per cent) were identifi ed in the fi rst herd, 400 out of 475 (84.2 per cent) and 256 out of 301 (85 per cent) animals were positive in the second and third herd. High number of animals with BVDV RNA was detected in all herds. The real-time PCR assay detected BVDV RNA in 5 of 1068 samples analyzed (0.5 per cent). 4 positive samples out of 490 (0.8 per cent) and 1 out of 301 (0.33 per cent) were found in the second and third herd. The genetic materials of BVDV were not found in the fi rst herd. Data on the number of PI animals were in accord with serological fi ndings in the cattle herds involved in our study. The genetic typing of viral isolates revealed that only BVDV, Type 1 viruses were present. The phylogenetic analysis confi rmed two BVDV-1 subtypes, namely b and f and revealed that all 4 viruses from the second farm were typed as BVDV-1b and all of them were absolutely identical in 5’-UTR, but virus from the third farm was typed as BVDV-1f. Conclusion. Our results indicated that the BVDV infection is widespread in cattle herds in the eastern Ukraine, that requires further research and development of new approaches to improve the current situation.