COMPARISON OF SERODIAGNOSTIC TESTS AND ULTRASONOGRAPHY FOR CYSTIC HYDATIDOSIS IN AN EPIDEMIOLOGIC-STUDY OF RURAL URUGUAY

Cystic hydatidosis (Cti) caused by Echinococcus granulosus is an impor tant zoonosis worldwide. Several serodiagnostic and ultrasound tests a re currently used for screening asymptomatic CH. The sensitivity of th e serodiagnostic tests has been demonstrated by several groups to be l ower than ultrasonography (US). To explain the mechanism of the differ ence in sensitivity, a large-scale US survey combined with an IgG4-enz yme-linked immunosorbent assay test was conducted in Uruguay, Our resu lts suggest that certain cyst images. e.g., multivesicular cysts, may be closely associated with a high antibody response regardless of the cyst size, whereas other hydatid lesions, e.g., solid images with/with out rolled parasite membranes, have lower antibody responses with a cl ose relationship to cyst size. Seropositivity of subjects who had been treated surgically for removal of hydatid cysts in the last 5 yr was closest to that of actual CI-E patients, albeit free from CH by US. Th ese findings are important for the proper use of scrodiagnostic tests and US for community-based epidemiological studies.