Transmission ecology of Echinococcus in wild-life in Australia and Africa.

Following the introduction of E. granulosus into Australia with domestic animals during European settlement, the parasite quickly became established in the E. granulosus-naive native animals of the continent. The distribution of E. granulosus in wildlife in Australia is restricted by rainfall, but nevertheless the parasite is currently widespread and highly prevalent in many areas including numerous national parks and privately owned farms. The human population of Africa is rapidly increasing resulting in ever more pressure on wild-life populations and habitat. National parks, reserves and conservation areas now provide important tracts of preserved habitat for maintaining populations of wildlife that are also important in the maintenance of E. granulosus. In some parts of Africa, hydatid-infected humans provide a source of E. granulosus infection to wildlife definitive hosts. In many areas felids may also act as important definitive hosts for E. granulosus with the parasite being maintained in a prey/predator relationship between lions and a range of intermediate hosts. Populations of E. granulosus-infected wild-life both in Australia and Africa act as important reservoirs in perpetuating the transmission of E. granulosus to both domestic animals and humans. In Australia, E. granulosus-infected wild-life is infiltrating urban areas and currently represents a potentially important new public health problem.