Global Comparative Phylogeography of E. granulosus s.s. Inferred From Mitochondrial DNA: Integrated Datasets of GenBank and Newly Characterized Isolates From Afghanistan.

Cystic echinococcosis (CE), caused by Echinococcus granulosus sensu stricto (E. granulosus s.s.), remains a major zoonotic disease of global public health importance. Afghanistan is considered endemic for CE; however, molecular data on circulating parasite populations are extremely scarce. This study aimed to characterize the genetic diversity, population structure, and global phylogeographic relationships of E. granulosus s.s. from Afghanistan within an integrated worldwide mitochondrial dataset. Hydatid cysts were collected from livestock hosts (cattle, sheep, and goats) in Afghanistan, and mitochondrial cytochrome c oxidase subunit 1 (cox1) and NADH dehydrogenase subunit 1 (nad1) genes were sequenced and analyzed alongside a comprehensive global dataset retrieved from GenBank. Genetic diversity indices, neutrality tests, median-joining (MJ) haplotype (H) networks, sliding-window analyses, and phylogenetic reconstructions based on concatenated mitochondrial sequences were employed. All Afghan isolates were identified as E. granulosus s.s., with a strong predominance of genotype G1 and only a single G3 isolate. Afghan populations exhibited moderate to high H diversity (Hd) but low nucleotide diversity, indicating closely related Hs separated by few mutations. Global H networks revealed star-like topologies with extensive intercontinental H sharing and no host- or geography-specific clustering. Phylogenetic and network analyses confirmed the genetic coherence of the G1 lineage worldwide and the limited diversity of G3. Sliding-window analyses showed genome-wide neutrality and absence of localized selective sweeps. Collectively, these findings position Afghan E. granulosus s.s. populations within a globally interconnected transmission network, highlighting the role of livestock movement and historical dispersal in shaping contemporary CE epidemiology. This study fills a critical regional knowledge gap and provides a robust phylogeographic framework to inform surveillance, control, and One Health interventions in endemic settings.