Federal Health Minister Nicola Roxon said health officials had decided to maintain Australia's level of "contain" except for in Victoria, the hardest-hit state, which is at "modified sustain" level.

Overnight WHO declared the swine flu outbreak a global influenza pandemic, the first time the organisation has upgraded its alert status to such a level in 41 years.

Director-general Margaret Chan said the pandemic was "moderate" and the alert upgrade did not mean the death toll from the virus would rise sharply.

Ms Roxon said that, in the vast majority of cases, swine flu would continue to have a mild effect.

``We believe we can continue with our targeted effort to treat those most at risk in Victoria and to continue to try and delay the community spread in those jurisdictions where there are not large numbers of cases,'' Ms Roxon said.

There are now 1336 cases of swine flu in Australia, with 1011 of those in Victoria, 115 in NSW, 77 in Queensland, 43 in Western Australia, 35 in the ACT, 31 in South Australia, 13 in Tasmania, and 11 in the Northern Territory.