A comparison of Echinococcus granulosus from different geographical areas of Australia using secondary cyst development in mice

Significant differences in the rate of development of secondary hydatid cysts of Echinococcus granulosus in the same strains of mice were demonstrated between the parasite of Tasmanian sheep origin and that from sheep in Eastern and Western Australia. Similar differences were also found between E. granulosus of macropod and sheep origin, from Eastern Australia. These results complement previous comparative studies on strobilar development and support the suggestion that at least three distinct strains of E. granulosus exist in Australia. Two are found in sheep, one on the mainland and the other in Tasmania and the third is perpetuated amongst macropods on the mainland. The value of secondary hydatidosis as a criterion for strain differentiation of Echinococcus is emphasised.