Abstract
Cystic echinococcosis (CE) is a zoonotic disease caused by the larval stage of the Echinococcus granulosus sensu lato (s.l.) complex. The disease is globally distributed, with particularly high prevalence in Central Asian countries, including Kazakhstan. Despite its significant impact on public health and livestock production, data on CE in sheep in Kazakhstan remain limited. This study investigated the prevalence and genetic diversity of Echinococcus granulosus sensu stricto (s.s.) in sheep across Kazakhstan, addressing an important zoonotic disease affecting both livestock and human health. Over the course of one year, a total of 31,389 sheep were examined, and cystic echinococcosis cysts were collected from the livers and lungs of 550 infected sheep across 14 regions of Kazakhstan. Molecular analyses targeting mitochondrial genes (nad1, cox1) were performed to determine genetic diversity. The results revealed a higher occurrence of CE in the southern regions of the country. Among the genotyped isolates (57), genotype G1 was dominant, accounting for 84.2% (48) of the samples, whereas genotype G3 (9) was detected at a lower frequency in three regions. A total of 11 distinct haplotypes were identified, indicating considerable genetic diversity among the isolates. Haplotype network analysis suggested gene flow among populations and revealed the widespread presence of the most common haplotype (EgKZ-2) across multiple regions. These findings highlight the need for continuous monitoring and targeted control strategies for cystic echinococcosis, emphasizing the importance of understanding parasite genetic diversity for public health interventions and livestock management in endemic areas. Overall, this study contributes to the understanding of the genetic diversity and transmission dynamics of E. granulosus s.s. in Central Asia.