Asymptomatic abdominal hydatidosis detected by ultrasonography.

Ultrasonography (US) and serology (double diffusion for antigen 5 (dd5] were used for the screening of hydatid disease in 1,418 asymptomatic individuals from two provinces in Argentina. A total of 122 positive subjects were identified and in 120 of them lesions consistent with hydatid disease were observed at US (98.4%) while only 19 had positive dd5 tests (15.8%). Chest radiography was performed in 647 of the subjects and an additional 4 lesions were found. Surgery was performed in 32 patients, confirming in all of them the sonographic diagnosis. It is suggested that US should be used in the screening for hydatidosis in high-risk populations as well as in follow-up programmes.