Risk analysis of the spread of cattle viral diarrhea in Kazakhstan

Abstract

Bovine viral diarrhea (BVD) is the most common infectious disease of cattle and is registered in many countries of the world. The disease causes significant economic damage to livestock, primarily due to a decrease in the reproductive capacity of infected animals. Infection of cattle during pregnancy results in transmission of the infection to the fetus, which can lead to embryonic death or the birth of persistently infected (PI) calves. PI-animals excrete BVDV in their feces and secretions throughout their lives, which is why they are the main pathway of transmission of the virus. Moreover, acute BVDV infection leads to transient viremia and immunosuppression, resulting in an increase in secondary infections. In recent years, outbreaks of BVD cattle have been reported in several regions of Russia and China bordering Kazakhstan, indicating a high risk of introducing the infection into the country. Although Kazakhstan is officially considered free from BVD cattle, there is ample evidence that this infection is present in many regions of the country. However, the lack of a clear understanding of the epizootic situation in the country in terms of BVD cattle does not allow the full use of effective control measures, such as total vaccination of livestock in regions at risk of infection. This article provides data on the epizootic situation in Kazakhstan on BVD cattle, as well as an epidemiological analysis of the risks of the spread of BVD cattle in the country.