Background: Giardia infection is an ongoing problem in Tasmania and occurs throughout the state. It has been postulated that part of the problem is the reservoir of infection in native animals which is suggested to contribute to infections in humans. To date, however, no detailed study on the epidemiology of giardiasis in Tasmania has been carried out.

Methods: Information regarding the prevalence of Giardia infection in humans and the risk of intrafamilial transmission was obtained from the Department of Community and Health Services and from the direct examination of human or animal fecal samples.

Results: Giardia has been found to be present in a wide range of native and domestic animals and in humans of all ages from all over the state.

Conclusions: Giardiasis is endemic in Tasmania and poses a risk to locals as well as to visitors to the state, especially those who participate in wilderness activities such as bushwalking. These people must be aware of the possible risk of Giardia infection and should take precautionary measures to avoid infection.