Global epidemiology of Cystic Echinococcosis

 “Echinococcosis” is a parasitic disease, with more than one million people estimated to be infected. Among Echinococcus spp. infections, CE which caused by the larval stage of the Echinococcus granulosus sensu lato (s.l.) species complex, is widespread and the most prevalent at the global level among human populations.

Five species of E. granulosus s.l. complex is now recognized, based on phylogenetic analysis and parasite host specificity in their life cycle; Echinococcus granulosus sensu stricto, Echinococcus equinus, Echinococcus ortleppi, Echinococcus canadensis and Echinococcus felidis.

CE is globally distributed and found in every continent (except Antarctica), in Africa, Europe, Asia, the Middle East, Central and South America, and in rare cases in North America (which E. granulosus is rarely reported in Canada and Alaska). Few human cases have been reported in Arizona and New Mexico.

In endemic regions, human incidence rates for CE can reach more than 50 per 100 000 person-years, and prevalence levels as high as 5%–10% may occur in parts of Argentina, Peru, East Africa, Central Asia and China. In Western and Northern Europe; after a successful control program, Iceland can be regarded as free of CE transmission since decades.

In central Europe, most of the CE cases diagnosed in humans have been classified as imported cases. In animals, no systematic data are available but slaughterhouse reports indicate that CE in livestock is nearly absent. And also no genetic data were available for several endemic or importing countries.

So much more collaborative work is needed to investigate the transmission of the species complex of E. granulosus s.l. and its potential clinical effects in humans. This is important in terms of providing a better understanding which parasitic species represents a public health problem, resulting in targeted control measures.

Pr Nazmiye ALTINTAS President of World Association of Echinococcosis / International Association of Hydatidology -President of Turkish Association of Hydatidology, İzmir Turkey