Detection of hydatid antigen in urine by countercurrent immunoelectrophoresis.

Hydatid antigen was demonstrated for the first time in the urine of patients with hydatid disease by countercurrent immunoelectrophoresis (CIEP). The antigen was detected in the concentrated urine of 7 of 16 (43.75% positive) patients with surgically confirmed hydatid disease, 4 of 10 (40% positive) patients with ultrasound-proven hydatid disease (daughter cysts or prominent septation and hydatid sands demonstrated by ultrasound), and 8 of 14 (57.14% positive) patients with clinically diagnosed (presumptive) hydatid disease. No antigen was detected in the concentrated urine from 24 patients with parasitic diseases other than hydatid disease. However, antigen was detected in 2 (8% false positive) of 25 concentrated urine samples collected from healthy control subjects (blood donors and students). These result suggest that the detection of hydatid antigen in the urine by CIEP is a simple, rapid, and noninvasive method of diagnosis of hydatid disease.