A case report of fatal disseminated cystic echinococcosis in a chimpanzee referred from a zoo in Shiraz City, Iran.

Cystic echinococcosis is a zoonotic disease caused by the larval stage of Echinococcus granulosus sensu lato (s.l.) and has been rarely reported in non-human primates. This report describes a fatal case of heavy cystic echinococcosis in an adult chimpanzee from a zoo in Shiraz city, southern Iran. Necropsy revealed hydatid cysts involving daughter cysts in the thoracic cavity, liver, spleen, and pericardium. The cyst rupture and leakage of hydatid fluid were observed in the thoracic cavity. This was considered the likely cause of animal death. Molecular analysis of cyst samples targeting the cox1 gene confirmed E. granulosus sensu stricto (s.s.), G1 genotype. The findings demonstrate that chimpanzees are susceptible to severe echinococcosis, highlighting the need for strict parasite control and environmental hygiene in zoological parks.