A description of human hydatid disease in Tasmania in the post-eradication era
Human hydatid disease, or echinococcosis, is a helminthic infection that leads to the formation of fluid-filled cysts in the liver, lungs and other organs. Echinococcus granulosus, which causes cystic echinococcosis, or unilocular cyst disease of viscera,1 is the only member of the genus Echinococcus to be found in Australia. It was introduced into Australia during the early period of European settlement and had been described in domestic animals before 1840.2
E. granulosus is a cyclozoonosis, requiring at least two species of vertebrates as definitive and intermediate hosts (Box 1). Dogs and other canids such as dingos and foxes are definitive hosts and infection occurs following ingestion of metacestodes (cysts) in mammalian organs, leading to the shedding of infective eggs containing larval oncospheres in the faeces. The intermediate host is infected following ingestion of infective eggs. The intermediate host range is broad and regionally specific.3 It includes domestic and feral ungulates such as sheep, goats, pigs, camels and buffaloes, and marsupials such as kangaroos and wallabies.