[Hydatidosis: new concepts in an old disease (First part) (author's transl)]

In the first part of this review several aspects of the classical echinococcosis due to E. granulosus are commented on (geographical distribution, morphological, epidemiological, taxonomic and pathogenetic characteristics). The real incidence of this disease in Spain is unknown due to the absence of global epidemiological data, especially by the lack of sero-epidemiological surveys. Epidemiological measures necessary to establish a control program for this zoonosis are recommended. In relation to the pathogenesis of the parasitosis, the authors mention some clinicopathologic characteristics which are conditioned to the anatomy and function of the organs where hydatids are located.