Immunodiagnosis of pulmonary hydatid disease in a patient with negative radiologic and scintillographic findings.

Hydatid disease was diagnosed by the arc 5 double diffusion (DD5) test in a patient with concomitant pulmonary disease. The localization of the cysts could not be determined by radiologic and scintillographic studies of the lung and abdomen. The hydatid nature of fluid collected by pleural puncture required for the concomitant infection, was established by using the aspirate as antigen in the DD5 test and five small pulmonary hydatid cysts were found at surgery.