Seroprevalence of Antibodies of Crimean-Congo Hemorrhagic Fever Virus in Cattle in the Turkestan Region of Kazakhstan

Background: Crimean-Congo hemorrhagic fever (CCHF) is endemic in southern Kazakhstan, yet data on livestock exposure remain scarce. Because cattle can amplify virus-infected ticks, accurate prevalence estimates are essential for risk-based control.Objectives: This study aimed to determine the seroprevalence of CCHF virus (CCHFV) antibodies in cattle across the Turkestan region and to identify demographic and spatial factors associated with exposure.Methods: In ۲۰۲۴, a cross-sectional survey generated ۸۴۰ bovine serum samples (۴۲۰ in spring and ۴۲۰ in autumn) from ۱۴ districts of the Turkestan Region, Kazakhstan. Sampling was performed using a random approach with stratification: ۴۲ rural settlements were included (۳ rural districts per district, and ۱۰ heads of cattle from each district). Animals were selected from multiple owners in each village, ensuring the data were representative for assessing the cattle population in the region. CCHFV antibodies were detected using a commercial double-antigen enzyme-linked immunosorbent assay (ELISA), which enhances specificity and reduces the risk of cross-reactivity with related viruses. Spatial variation in seroprevalence was visualized in ArcGIS ۱۰.۸, while statistical analysis, comprising descriptive summaries, χ² test, and multivariable logistic regression, was conducted in R software, version ۴.۱.۰. Odds ratios (OR) with ۹۵% confidence intervals (CI) were calculated. Results with P=۰.۰۵ were deemed significant.Results: The overall seroprevalence was ۳۶.۲%, with a significant range of district-level seroprevalence from ۱۰% to ۷۶.۶%. The study identified higher seropositivity in adult cattle (۴۳.۴۲%) than in juveniles (۱۱.۸۶%), and females had slightly higher rates than males (۳۸.۳۲% vs ۲۹.۹۹%). Logistic regression analysis showed that age was a significant risk factor, with adults having ۴.۰۶ times higher odds of seropositivity (OR=۴.۰۶; ۹۵% CI, ۲.۶۲%, ۶.۲۹%) compared to juveniles. Conclusion: The findings confirm active, heterogeneous circulation of CCHFV among cattle in the Turkestan region, with older animals and districts practicing communal grazing at greatest risk. Incorporating livestock serosurveillance into routine tick control programs and focusing interventions on identified hotspots could curtail zoonotic spill-over to humans.

کلیدواژه ها:

Antibodies ، Cattle ، Crimean-Congo hemorrhagic fever (CCHF) ، Kazakhstan ، Ticks