In a groundbreaking study that sheds new light on the epidemiology and genetic diversity of a globally significant parasitic pathogen, researchers have unveiled detailed genetic insights into Echinococcus granulosus sensu stricto (s.s.) strains circulating in ruminant populations across Greece. This investigation integrates fresh data from Greece with previously reported findings from Türkiye and neighboring Balkan and Mediterranean countries, providing a broader geographical and evolutionary context for understanding the transmission dynamics of this notorious zoonotic parasite.
Echinococcus granulosus sensu stricto is the primary causative agent of cystic echinococcosis (CE), a serious parasitic zoonosis with substantial public health implications, particularly in regions where livestock husbandry is a major economic activity. The life cycle of this parasite involves definitive hosts, typically canids, and intermediate hosts such as sheep, goats, and cattle, where larval cysts develop in internal organs. Accurate characterization of the genetic variants of Echinococcus species is critical for unraveling transmission patterns, improving diagnostic strategies, and tailoring effective control measures.
The study’s authors employed a robust molecular approach, utilizing mitochondrial DNA sequencing markers to characterize parasite isolates collected from naturally infected ruminants throughout Greece. This genetic characterization allowed them to ascertain the specific genotypes present, correlate these genotypes with host species and geographic origins, and contrast these findings with data obtained in similar epidemiological settings in Türkiye and the wider Balkan and Mediterranean regions.
One of the most striking revelations was the predominance of the G1 genotype, commonly referred to as the “sheep strain,” among the Greek isolates. Molecular evidence confirmed that this genotype remains the most widespread and epidemiologically significant variant across southern Europe and parts of the Near East. The G1 strain’s prevalence underscores its critical role in sustaining transmission cycles involving domestic sheep and dogs—the primary reservoir and definitive host reservoir species, respectively.
Interestingly, the study noted sporadic detection of other genotypes, such as G3, which is often associated with cattle as the intermediate host. These findings mirror genetic diversity patterns observed in Türkiye and surrounding regions, highlighting the porous nature of genetic flow across national borders due to livestock movements, trade, and shared grazing pastures. Such transboundary parasitic dispersal emphasizes the necessity of coordinated regional efforts for surveillance and control.
The genetic homogeneity observed within the Greek isolates suggests a relatively stable parasite population structure, which could reflect longstanding endemicity coupled with consistent transmission mechanisms. However, subtle genetic differences identified among isolates denote ongoing microevolutionary processes influenced by host species, ecological pressures, and anthropogenic factors such as farming practices and dog population management.
Furthermore, this study elucidates phylogeographic patterns by constructing haplotype networks and phylogenetic trees that map the relationships between Greek Echinococcus isolates and those from adjacent countries. This comprehensive genetic mapping provides invaluable insights into historical migration routes of the parasite and potential introductions of novel strains, information pivotal for anticipating emerging parasite variants and potential shifts in virulence or host specificity.
Importantly, the research draws attention to the continuous risk posed by cystic echinococcosis, particularly in rural and pastoral communities where close livestock–canid interactions facilitate transmission. This is compounded by challenges in the implementation of effective veterinary public health measures, such as deworming of dogs, safe disposal of infected offal, and public education about parasite transmission cycles.
Advanced molecular diagnostics applied in this study also reveal the limitations of traditional morphological identification techniques, which cannot reliably differentiate between closely related genotypes. The reliance on molecular markers therefore enhances surveillance sensitivity and specificity, enabling more accurate epidemiological mapping and outbreak investigation.
The cross-national comparison with Türkiye and Balkan parasitic populations also highlights varying prevalence rates and genotype distributions that may be influenced by differences in animal husbandry systems, climatic conditions, and cultural practices. This comparative approach provides a template for future multinational collaborative efforts aimed at controlling this neglected tropical disease.
Significantly, the insights afforded by this genetic study extend beyond academic interest, bearing direct implications for disease control policies. Tailored intervention strategies can now be better designed by taking into account the dominant genotypes in specific regions, improving vaccine development prospects, and refining diagnostic protocols to detect early infections and prevent human cases.
The findings affirm the critical importance of integrated One Health approaches, linking human, animal, and environmental health disciplines to tackle the complex lifecycle of Echinococcus granulosus s.s. Harnessing molecular epidemiology tools to monitor parasite populations enhances the capacity to predict and respond to shifts in parasite dynamics driven by environmental changes, economic developments, and global trade.
This study also represents a valuable addition to the growing body of knowledge that maps genetic diversity hotspots of Echinococcus granulosus s.s. in the Mediterranean basin, a region historically recognized as endemic but currently facing dynamic shifts due to modernization and changing agricultural landscapes.
In sum, the genetic characterization of Echinococcus granulosus s.s. reported in this research not only fills crucial knowledge gaps for Greece but also reinforces the notion that regional genetic variation of this parasite is intricately linked to the ecology and socio-economic fabric across southeastern Europe and western Asia. Understanding these patterns is indispensable for formulating sustainable CE control programs that ultimately reduce the burden of this debilitating zoonosis on vulnerable communities.
As scientific and veterinary communities strive to mitigate the impact of parasitic diseases, such integrative molecular investigations underscore how genomic epidemiology can revolutionize parasite monitoring, inform public health strategies, and contribute to global efforts against neglected tropical diseases. This endeavor thus marks a significant step forward in the genetic surveillance of Echinococcus granulosus s.s., promising improved outcomes for both human and animal health in endemic regions.
Subject of Research: Genetic characterization of Echinococcus granulosus sensu stricto in ruminants from Greece, with comparative analysis involving Türkiye and the Balkans/Mediterranean region.
Article Title: Genetic Characterization of Echinococcus granulosus sensu stricto from Ruminants in Greece. Comparison with Findings in Türkiye and Reports from the Balkans and Mediterranean Countries.
Article References:
Roinioti, E., Bossis, I. & Simsek, S. Genetic Characterization of Echinococcus granulosus sensu stricto from Ruminants in Greece. Comparison with Findings in Türkiye and Reports from the Balkans and Mediterranean Countries. Acta Parasit. 70, 158 (2025). https://doi.org/10.1007/s11686-025-01084-1
Image Credits: AI Generated
