Epidemiological study on reproductive pathogens with particular focus on Bovine Viral Diarrhoea Virus in dairy cattle in Tajikistan :

Abstract: Bovine Viral Diarrhoea Virus (BVDV) is considered to be one of the most important infectious diseases of cattle. It causes substantial economic losses worldwide mainly due to reproductive disorders. Neospora caninum and Brucella abortus are other important diseases causing major economic losses due to reproductive failure. B. abortus is also an important zoonotic disease and many countries, like Tajikistan, have a vaccination program in order to control the disease. Tajikistan, located in Central Asia, is a country where approximately 80% of the households own livestock. Many people are dependent on their cattle for survival. Reproductive disorders among cattle can therefore be greatly disadvantageous to the work on reducing poverty in the country. The aims of this study were primarily to investigate the occurrence of BVDV in the western Tajikistan among dairy cattle and to study risk factors relevant for controlling the disease. The secondary aim was to investigate the occurrence of the differential diagnoses N. caninum and B. abortus among dairy cattle in the western Tajikistan. In total, 305 serum samples were collected from six governmental farms and four private farms. The samples were analysed for presence of antibodies to BVDV, N. caninum and B. abortus. Bulk milk was also collected from five governmental farms and one private farm and analysed for presence of antibodies to BVDV. The overall seroprevalence of BVDV was 77%. Governmental farms had higher seroprevalence than private farms. Young animals in private farms had lower seroprevalence than young animals in governmental farms. This might indicate that within the private farms there was ongoing self-clearance of BVDV. The overall seroprevalence of N. caninum was 21%. The seroprevalence was higher in private farms than in governmental farms. This might be due to more frequent horizontal transmission within the private farms. This is the first report, to my knowledge, of infection with BVDV and N. caninum in Tajikistan. The overall seroprevalence of B. abortus was 11%. Two thirds of the animals in this study were vaccinated against B. abortus. Although the seroprevalence was mainly due to vaccination, the results indicate that there was infection with B. abortus in the study area.