Morphological and molecular study of hydatidosis in sheep in Diyala province

Abstract

Hydatidosis, formerly called Iraqi cancer, is a highly endemic disease in Iraq and has an extensive effect on livestock productivity and human health. One hundred sheep organs (liver, lung, and spleen) were examined for the detection of hydatid cysts from different butcher shops and slaughterhouses in various areas of Diyala Governorate. Gross examination showed a white or yellowish-white layer on the surface of the external organ; they appeared as spherical or ovoid, fluid-filled sacs within organs resembling a bubble, particularly in the liver, lung, and peritoneum. The total hydatidosis infection rate in sheep was 15%; females recorded a high infection rate of 22%, while the lowest rate appeared in males at 8%. The liver recorded the highest rate, reaching 15%, while the second rate in the lung was 11%, and the lowest rate in both the spleen and peritoneum was 1%. The adult age group (36-48 months) recorded the highest rate, 40%; the lowest rate was registered in younger sheep (6-12 months), 0%. The molecular analysis method depending on conventional PCR using specific primers for E. granulosus was isolated from sheep viscera (liver, lung, and spleen). A partial fragment of a repetitive DNA sequence of E. granulosus of 308 bp was successfully amplified. The isolated strains in this study and the encoding DNA repetitive sequences from E. granulosus were deposited in GenBank. The identity of the local E. granulosus isolate from sheep in the Diyala area showed a high identical relation (100%) with the Iraq isolate in previous studies in accession number OP272486, while the global isolate strain was recorded at rates of 99.565%, 99.13%, and 99.13% from Argentina, Brazil, and Turkey, respectively. Background: Hydatidosis, or cystic echinococcosis (CE), is a chronic zoonotic parasitic disease caused by the larval stage of the cestode Echinococcus granulosus sensu lato and represents a significant public health and economic concern in many livestock-raising regions worldwide. Animal husbandry societies have encountered echinococcosis for many years. The first written references are from the Talmud, which describes lesions of hydatid cysts. Clinical references were also made by the Greek physician Galen in the second century AD and Persian polymath Rhazes in the ninth century AD, and they characterized fluid-filled cysts of both animals and humans. However, for over a millennium, the true parasitic origin of cysts remained a mystery, with prevailing theories of spontaneous generation and imbalances in the body humor.