Detection of specific hydatid antigens and antibodies in serum and urine of experimentally infected sheep M. Ghorbanpoor a, * , M.H. Razi Jalali a , N. Hoghooghi Rad a , L. Nabavi a , S. Esmail Zadeh a , A. Rafiei b , M.R. Haji Hajikolaei c a Department of Pathobiology, Faculty of Veterinary Medicine, University of Shahid Chamran, Ahvaz, Iran b Infectious and Tropical Disease Research Center, Jundishapour University of Medical Sciences, Ahvaz, Iran c Department of Clinical Science, Faculty of Veterinary Medicine, University of Shahid Chamran, Ahvaz, Iran Received 17 February 2005; received in revised form 7 June 2006; accepted 21 June 2006 Abstract Immunodiagnostic confirmation of cystic human hydatidosis is frequently required before surgical intervention or of chemotherapy. However, it remains inadequate to detect specific antibodies or antigens in some confirmed cases of echino- coccosis. This study was carried out to investigate the accuracy of three different immunodiagnostic tests for detection of specific circulating antigens or antibodies in the serum and urine of 13 experimentally infected sheep. For this purpose, Echinococcus granulosus were collected from small intestine of experimentally infected dogs, and 2000 taenid eggs were orally administered to each of the 13 sheep. There were six other sheep, which were kept as the control group. Biweekly serum and urine samples were collected from all the sheep for 4 months after infection. The sera were subjected to indirect hemagglutination test and the concentrated urine samples were subjected to coagglutination and counter immunoelectrophoresis tests. The results revealed that the sensitivity of these tests in detecting the hydatid antigens in the urine or antihydatid antibodies in the serum of the infected sheep reached their maximum in 12th and 13th week after infection; then it decreased in the following weeks. Examination of the non-infected sheep samples throughout the experiment showed that the aforesaid findings were specific only to the infected sheep. It seems that the appearance of specific hydatid antigen in urine and its antibodies in the serum were simultaneous. Although these tests are highly specific, false negative outcomes were encountered in their detection of cystic echinococcosis. In general, it seems rational to establish some series of diagnostic procedures in order to reveal antibodies and antigen of metacestode in serum and urine of the patients. # 2006 Elsevier B.V. All rights reserved. Keywords: Hydatid cyst; Sheep hydatidosis; Echinococcus granulosus; Coagglutination test; IHA; CIEP 1. Introduction Cystic hydatid disease, caused by the larva (hydatid cyst) of the dog tapeworm, Echinococcus granulosus, is a major infection having worldwide distribution and variable geographic incidence. Human infection is common in countries where sheep and cattle rearing constitute an important industry. Specific diagnosis of hydatidosis is based on immunodiagnostic methods supplemented with radiological and ultrasound exam- ination. Diagnosis of the condition is important not only for detection of cases for surveillance of the disease in the community but also for monitoring the impact of its control program in the area (Parija, 1998). www.elsevier.com/locate/vetpar Veterinary Parasitology 142 (2006) 91–94 * Corresponding author. Tel.: +98 611 3330073; fax: +98 611 3360807. E-mail address: ghorbanpoor@scu.ac.ir (M. Ghorbanpoor). 0304-4017/$ – see front matter # 2006 Elsevier B.V. All rights reserved. doi:10.1016/j.vetpar.2006.06.018