Australia confirmed its second and third cases of swine flu on Wednesday, including a 9-year-old boy whose primary school class was quarantined.
Both of the two patients - one each in the country's two largest cities of Sydney and Melbourne - had recently returned from the United States, where many of the world's cases are.
Neither was seriously ill, health officials said.
New South Wales state Health Minister John Della Bosca said a woman from Sydney who returned from the US last week had tested positive for swine flu.
The woman had been given antiviral drugs before boarding the flight and was not contagious at the time, he said.