UTTAR PRADESH JOURNAL OF ZOOLOGY

Cystic echinococcosis (CE) ; a zoonotic infection caused by species of tapeworms belonging to the Echinococcus granulosus complex. It is caused by hydatid cysts, usually involving the liver and lungs, with a potentially fatal outcome in untreated patients. The study aims to detect and characterise Echinococcosis (hydatid cysts) in sheep in Al-Najaf, Iraq, through macroscopic and microscopic examination, and to understand the prevalence and pathology of the infection. The study was conducted at the Al-Najaf slaughterhouse, Iraq from September 2023 to December 2023. Fifteen livers containing hydatid cysts were obtained for examination of macroscopic and microscopic findings, as well as the number and size of the cysts. Twenty-three cysts were identified in the gross examination of the livers. The external wall of the hydatid cysts revealed hydatid sand similar to free protoscoleces and/or brood capsules, which appeared as multiple small white particles varying in size. Microscopic examination of hematoxylin and eosin-stained sections showed cysts containing a thick wall and many irregularly interwoven folds, extending into the lumen of the cyst, whose contents appeared laminated; it was translucent to white, yellow gelatinous. The adjacent hepatic parenchyma exhibited a chronic inflammatory response with a peripheral fibrous membrane wrapping the cyst, characterised by cellular infiltration by mononuclear inflammatory cells, including eosinophils and neutrophils, as well as macrophages and fibrocytes. In conclusion, the presence of multiple lesions involving different hepatic lobes in individual sheep was observed at necropsy, which was confirmed as a hallmark finding in diagnosis through gross and microscopic examination. The study recommends the application of molecular techniques to identify circulating Echinococcus genotypes in sheep, thereby achieving a higher degree of characterization of local epidemiology.