An experimental model of hydatidosis in rabbit testis

Although no part of human anatomy is invulnerable to hydatid disease, it has been reported to occur in most of vital organs. Hydatid disease of urinary tract is uncommon, accounting for only 2-3 % of all such cases. Testes are extremely rare sites for echinococcosis. There are only three cases of testicular hydatid disease which were reported. In this laboratory animal model, we studied echinococcosis in rabbit testis. In this experimental trial study, 14 male Albino rabbits (body weight 2.5-3kg) were randomized into two groups: group A (study group), for testicular injection and group B (control group), for intraperitoneal injection of viable protoscoleces. All rabbits were infected, and then housed them under pathogen-free conditions for 10 weeks (70 days). One rabbit from group A and three from group B died one day after injection, and the other rabbits survived during follow-up period. At 10th week they were all anaesthetized and then we studied all testes with ultrasonography. In group A all testes were excised, and in group B we removed liver, kidneys and took four biopsies from peritoneum, for histopathology investigation. There was demonstrable hydatid cyst (protoscoleces and germinative layer) in testes of five rabbits from group A, but in one rabbit both testes were normal. In group B, three out of four rabbits developed peritoneal hydatidosis. The mechanism of testicular resistance to echinococcosis could be blood-testis barrier because when we directly infected the testes of rabbits with protoscoleces, hydatid cyst developed.