Prevalence of Echinococcus granulosus (Cestoda: Taeniidae) Infection in Stray Dogs and Local Herbivores in Al-Kharj, Saudi Arabia

Abstract

Background: Echinococcus granulosus is a cyclophyllid cestode parasite that lives as an adult in the intestine of canids and is the most common cause of hydatidosis in ruminants (intermediate hosts). It also offers a public health risk because of the possibility of human infection. The incorrect disposal of dead animals, access of farm dogs to the internal organs of sheep and grazing in areas with wayward dogs are the most common production methods that might increase the risk of sheep being exposed to hydatidosis. The purpose of this study was to investigate the natural spread of E. granulosus infection in wayward dogs, as well as the sterility and fertility rates of hydatid cysts in herbivores of Al-Kharj (Saudi Arabia). Methods: Fecal samples from 150 dogs were collected from several locations in Al-Kharj (Saudi Arabia) where livestock rearing takes place and the existence of wayward and semi-feral canines from August 2021 to February 2022. Parasitic eggs were recovered from fecal samples using the flotation method, followed by centrifugation at 1200 × g. Examination of slaughtered animals was done by comprehensive visual examination, palpation and incision of the internal organs, including lungs, liver, muscles, kidneys and heart. All hydatid cysts detected in the organs were collected for cyst count, cyst fertility testing and protoscolices viability testing. Examination of cysts and viability of protoscolices. A 0.1% aqueous solution of eosin stain was used to examine the survival of protoscolices. According to Smyth and Barret (1980), deceased protoscolices became stained (purplish-red color) five minutes after exposure to staining, whereas living protoscolices remained colorless (recorded as alive) under the microscope. Result: 1698 sheep, 450 goats and 240 camels (slaughtered in Al-Kharj Abattoir) were examined as to their livers, lungs, muscles, kidneys and hearts were checked for hydatidosis. In a study of 150 dogs, 21 (14%) were shown to be naturally infected with E. granulosus eggs. Hydatid cysts were also identified in 156 (9.18%) sheep, 36 (7.5%) goats and 24 (10%) camels. In comparison to other tissues, the liver and lungs had the highest percentage of infestation, with values of 50.6% and 25.6% in sheep, 58.3% and 16.6% in goats and 66.6% and 16% in camels, respectively. The older age groups had higher infection rates than the younger ones. The highest percentage was seen in sheep over the age of 12 months (10.4%) and camels over the age of 6 years (12%). Hydatidosis is a serious economic and zoonotic problem. Therefore, we should take preventative measures in Al-Kharj city to avoid environmental pollution and infection of both humans and animals.