Hydatidosis in slaughtered sheep and goats in India: prevalence, genotypic characterization and pathological studies

The present study determined the prevalence of hydatid cysts in different organs of slaughtered hilly 'Gaddi' breed small ruminants-sheep (n = 230) and goats (n = 197)-in Kangra Valley of the north-western Himalayas, India. Hydatid cysts were found in 12.2% (n = 28) of sheep and 10.7% (n = 21) of goats. Pulmonary echinococcosis was more prevalent in slaughtered sheep and goats (sheep 56.36%; goats 62.90%) than hepatic echinococcosis (sheep 43.64%; goats 37.10%). Fertility rates were higher in hepatic (81.25%) and pulmonary cysts of sheep (83.87%) compared to goats. Molecular identification and genotypic characterization of Echinococcus granulosus isolates were based on mitochondrial cytochrome oxidase 1 gene (mtCO1). The genotypic characterization identified the isolated strain to be closely related to the G7 genotype. Histopathological examination revealed a thick coat of granulation tissue, causing fibrosis and inflammatory reaction composed of fibroblasts and mononuclear cells around the cysts. In the liver, hepato-cellular degeneration was prominent at the periphery of the cysts. The present study highlights the molecular confirmation and phylogenetic analysis of E. granulosus isolates with the prevalence of hydatidosis in a naïve host species and in an unexplored region. The findings are of significant medical and veterinary importance regarding development of control measures to check dissemination of hydatidosis.