Cystic echinococcosis: Future perspectives of molecular epidemiology

- Cystic echinococcosis (CE) caused by E. canadensis is not rare but more common than we previously expected.
- All clinical, pathological and epidemiological indices of CE are based on data and observations that conflate recognition of E. granulosus s. s. and E. canadensis at least.
- Molecular identification of the causative species of CE cases is essential for better understanding of CE.

Human cystic echinococcosis (CE) has been considered to be caused predominantly by Echinococcus granulosus sensu stricto (the dog-sheep strain). Molecular approaches on CE, however, have revealed that human cases are also commonly caused by another species, Echinococcus canadensis. All indices for classification and standardization of CE pathology including available images, epidemiology, diagnostics and treatment are currently based largely on a mixture of infections which include at least E. granulosus s.s. and E. canadensis. Involvement of other species of Echinococcus in CE including E. ortleppi or otherwise cryptic diversity demonstrated recently in Africa requires further elucidation. Molecular identification of the causative species in CE cases is essential for better understanding of pathogenesis and disease. This article stresses the importance of molecular species identification of human CE as a foundation for re-evaluation of evidence-based epidemiology.

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