Investigation of Live-Stock Animals Seroprevalence to West Nile Virus in the Territory of the Saratov Region

Aim – to determine the intensity of West Nile virus circulation in anthropogenic biotopes in the territory of the Saratov Region between 2012 and 2017. Materials and methods. 1454 blood serum samples from animals of private households and agricultural cooperatives in 14 districts of the Region were investigated: 1111 samples from horses and 343 samples from the cattle. Sera were examined for the presence of total antibodies to WNV using a test system registered in the Russian Federation to detect antibodies to this virus by a competitive enzyme immunoassay «ID Screen West Nile Competition Multi-species» («ID. Vet», France). Results and discussion. The share of resistant to WNV cohort of live-stock animals in the territory of the Saratov Region over the whole period of study was (14.0±0.9) %, particularly in horses – (15.9±1.1) %, and in the cattle – (7.9±1.5) %. The highest values were observed for horses. High level of resistance in live-stock animals was registered in the districts located on the left bank of the river Volga: central ones – Engels (36.4±5.5), Fedorovsky (29.0±4.6), and Sovetsky (20.0±3.7); southern districts – Rovensky (74.3±5.3 %) and Krasnokutsky (15.7±4.4), which confirms the assumption about the initial introduction of the virus from neighboring territories of the Volgograd Region into the territory of the Left Bank where there are characteristic near-water biotopes and active circulation of the agent takes place. The data obtained on the detection of the resistant live-stock animal cohort testify to the spread of West Nile virus in the territory of the surveyed districts of the Saratov Region and, in particular, anthropogenic biotopes which further points to the formation of persistent natural and natural-anthropourgic foci of West Nile fever