Malaria in a changing world: an Australian perspective.

Three elements must be present for endemic malaria: infected humans, susceptible mosquitoes and a suitable climate. All three occur in parts of Australia and yet this country has always been a region of marginal malaria endemicity. With the exception of a large epidemic in Cairns during the Second World War, most outbreaks have occurred in small, isolated populations of the Northern Territory. The last epidemic was at the Roper River Mission in the Northern Territory in 1962. Since Australia was declared to be free of endemic malaria in 1983, only sporadic cases of local transmission have occurred. There have been suggestions that future climate change may increase the range of the major vector in Australia, Anopheles farauti, and consequently lead to the re-establishment of endemic malaria. This possibility is discussed in relation to experiences in this and other regions. It is stressed that climate change in only one component in a complex epidemiological setting, and that other aspects such as human activity are probably more important.