Cystic echinococcosis in the Kyrgyz Republic: A comparative post-slaughter study of prevalence and pathomorphology in sheep and cattle

Abstract Background : The study aimed to assess the prevalence of cystic echinococcosis (EC) in sheep and cattle under conditions of natural enzootic conditions and the morphological features of EC. Methods : The methodology included 3 years of field monitoring (2017–2019) in six regions of the Kyrgyz Republic using pathological examination and histomorphological analysis of internal organs of 2281 cattle and 1306 sheep. All the detected cysts were classified based on the degree of invasion, organ localisation, biological condition and morphological maturity. Results : The results demonstrated a significantly higher prevalence in sheep (15%) compared to cattle (6%), indicating their increased susceptibility. The maximum values were found in the Naryn region at 45% in cattle and 26% in sheep, with a clear predominance of infection in females (up to 83.7%) and adults (up to 95.4%). In cattle, limited foci with isolated liver damage were predominantly recorded, while in sheep, a high number of severe and multi-organ forms were observed. Histological examination revealed a characteristic three-layered structure of fertile cysts, with the presence of protoscolex, lymphoid follicles and granulomatous reaction. The sterile forms showed caseous and calcified changes, especially pronounced in sheep. Differences in the morphology and degree of inflammation reflect the specificity of the species-specific immune response. Conclusions : Comprehensive comparative analysis highlights the key role of sheep in the epizootic transmission chain, the need for regular deworming of dogs, monitoring of older age groups and the development of regionally adapted prevention strategies.