EPIZOOTIC SITUATION OF BLUETONGUE IN SHEEP IN THE REPUBLIC OF KAZAKHSTAN BASED ON RESEARCH RESULTS IN 2021-2025

Abstract

The article presents the results of a study of biological samples collected from sheep from farms located in various regions of the Republic of Kazakhstan. The study aimed to assess the epizootic situation of bluetongue disease. A total of 25 samples were collected: 15 samples were tested using real-time reverse transcription polymerase chain reaction (RT-qPCR) with the MagMAX™ Viral RNA Isolation Kit (Applied Biosystems), and 10 samples were tested for antibodies against BTV VP7 using the ID Screen® Bluetongue Competition ELISA Kit (ID-Vet, France). Total RNA was extracted from 15 EDTA-anticoagulated blood samples using the MagMAX™ Viral RNA Isolation Kit (Applied Biosystems) as per the kit instructions for use. For the competitive ELISA (c-ELISA), absorbance (optical density) was measured at a wavelength of 450 nm. Reverse transcription and amplification were performed using the Applied Biosystems 7500 Fast Real-Time PCR System using the following thermocycling conditions: 45°C for 10 min, 95°C for 10 min, followed by 40 cycles of 95°C for 15 s and 60°C for 45 s. All 25 biological samples tested using modern, highly sensitive diagnostic methods yielded negative results, indicating the absence of bluetongue virus circulation in sheep farms in the Republic of Kazakhstan during the period 2021–2025.