A rare case of cerebral hydatidosis caused by a G1 genotype of Echinococcus granulosus in a cow from Iran M. Moazeni 1 , A. Oryan 2 *, H. Sharifiyazdi 3 , O. Amrabadi 2 and M. Akbari 1 1 Department of Parasitology, School of Veterinary Medicine, Shiraz University, Shiraz, Iran: 2 Department of Pathology, School of Veterinary Medicine, Shiraz University, Shiraz, Iran: 3 Department of Clinical Sciences, School of Veterinary Medicine, Shiraz University, Shiraz, Iran (Received 14 March 2015; Accepted 18 August 2015; First Published Online 17 September 2015) Abstract Hydatidosis is a medically and veterinary important parasitic disease that is endemic in many parts of the world. Unilocular hydatid cysts may develop in almost any part of the body. Up to 70% of hydatid cysts are located in the liver, followed by 25% in the lungs. Cerebral hydatidosis is an uncommon manifestation of the disease, occurring in less than 1/1000 infected hosts, yet diagnosis does pose a problem. We have reported an exceptionally rare case of cerebral hydatidosis in cattle. This is the first report to describe the characteristic pathological features of the cerebral hydatidosis in cattle caused by the G1 genotype of Echinococcus granulosus. Genotypic analysis was performed on a hydatid cyst from a cow originating from southern Iran, based on the sequence analysis of the cox1 mitochondrial gene. Introduction Cystic echinococcosis (CE) is a parasitic disease resulting from the infection of various organs by the encysted larvae of Echinococcus granulosus. This tape- worm is prevalent in most parts of Iran (Ahmadi & Dalimi, 2006). The life cycle of E. granulosus involves dogs and other carnivores such as jackals, foxes and wolves as the definitive host, and sheep and other herbivores as the intermediate host. The oncosphere hatches from ingested eggs in the intestine and enters the portal circulation in the intermediate host. The liver, being the first filter, is the most commonly involved organ, followed by the lungs. Up to 70% of hydatid cysts are located in the liver and 25% in lungs. Once within the systemic circulation, the larva may settle and develop into a hydatid cyst in other organs of the body. Although hydatid cysts can occur in any organ, it is very rare to see a cyst in the brain (Mandal & Mandal, 2011). Cerebral hydatid disease is very rare in humans, representing less than 1% of all cerebral space- occupying lesions, even in countries where the disease is endemic (Gana et al., 2008; Nemati et al., 2010). It has also been reported rarely in animal species (Singh et al., 1988; Ruas et al., 1997). It has been shown that E. granulosus has wide intra-specific variation, affecting the epidemiology, morphology, pathology, genetics, biology, physiology and control of cystic echinococcosis (Thompson & McManus, 2002). According to the mitochondrial DNA (mtDNA) sequences, ten distinct genotypes of E. granulosus, including G1 (common sheep), G2 (Tasmanian sheep), G3 (water buffalo), G4 (horse), G5 (cattle), G6 (camel), G7 (pig), G8 (cervid), G9 (human) and G10 (Fennoscandian cervid) have previously been recognized (McManus, 2002; Lavikainen et al., 2003; Maravilla et al., 2004; Hu¨ ttner et al., 2008). With regard to the recent taxonomic revisions, E. granulosus has been classified into four species, namely E. granulosus sensu stricto (G1 – G3), E. equinus (G4), E. ortleppi (G5) and E. canadensis (G6–G10) * Fax: þ987112286940 E-mail: oryan1215@gmail.com Journal of Helminthology (2016) 90, 634–637 doi:10.1017/S0022149X1500084X q Cambridge University Press 2015