Abstract
<jats:p>In 2023–2025, comprehensive monitoring of West Nile fever (WNF) was conducted across 14 regions of the Republic of Kazakhstan to assess virus circulation in natural foci. The study included the main potential reservoirs and vectors of the pathogen, namely wild migratory birds, mosquitoes, ixodid ticks, and bats. A total of 362 biological samples from wild birds, 84 samples from bats, 679 ticks, and 1,554 mosquitoes were examined. Laboratory diagnostics were performed using polymerase chain reaction (PCR) with primers specific to West Nile virus. According to the results, West Nile virus RNA was detected exclusively in wild birds—in 5 of 362 samples, corresponding to a prevalence of 1.38 % (95 % CI: 0.45–3.19 %). No West Nile virus RNA was detected in samples obtained from mosquitoes, ticks, or bats. Positive samples were detected in wild birds from the Pavlodar and Karaganda regions. The obtained data confirm the leading role of migratory birds in the introduction of West Nile virus into the territory of Kazakhstan and indicate the need for continued systematic epizootiological and molecular monitoring to assess the risk of the formation and maintenance of natural infection foci.</jats:p>