Cystic echinococcosis in the sheep: causes of its persistence in Sardinia.

The authors analyse the current epidemiological situation of sheep Cystic Echinococcosis (CE) in Sardinia, where the prevalence of ovine CE is still very high (70%) and this parasitosis is also frequently found in the human population. For this reason Sardinia represents a peculiar model for CE study, because there are particular conditions that allow Echinococcus granulosus to complete its life cycle. Some social and economical factors support the persistence of sheep CE: over 3 million Sarda breed heads are extensively bred; the presence, at farm level, of a strong relationship between dog, sheep and human; the low commercial value of meat coming from adult sheep, which results in a large number of sheep being slaughtered at home or on the farm rather than in authorized slaughterhouses. Moreover Sardinia is the only Italian region where partially successful echinococcosis control plans have been applied. The authors suggest some indirect and direct initiatives, including the use of a new vaccine against the development of this metacestode in sheep, to reduce the prevalence of CE.