Serological Investigations on West Nile Virus in Horses in Kazakhstan

This study presents the first investigation of West Nile virus (WNV) seroprevalence among farmed horses in Kazakhstan. In 2024, a total of 368 serum samples were collected from horses across 106 settlements in 10 regions of the Republic of Kazakhstan. Using an enzyme-linked immunosorbent assay (ELISA), antibodies to WNV were detected in 32 horses (8.7%; 95% CI: 6.2-12.0%) from six regions. Among the seropositive animals, 26 (81.25%) were females and 6 (18.75%) were males, ranging in age from 1 to 19 years. No statistically significant association between sex and the presence of antibodies to WNV was found in any of the six regions. Significant differences between age groups were observed in Aktobe (χ² = 12.16; p = 0.002) and Turkestan (χ² = 4.20; p = 0.040). In the remaining regions (Almaty, Zhetisu, West Kazakhstan, and Atyrau), no significant age-related differences were recorded (p > 0.05). These findings confirm the circulation of WNV among horse populations in Kazakhstan and highlight the practical value and effectiveness of using horses as sentinel indicators for WNV surveillance.