At least four people who were travelling on the Pacific Dawn cruise that arrived in Sydney this week have been diagnosed with swine flu.

A number of Gippsland residents were travelling on that South Pacific cruise.

A Traralgon resident, her son and her Sale-based mother were among the locals caught up in the drama.

The woman, who didn't want to be named, said she had flown back to Melbourne from Sydney when they received the call that they had to be quarantined.

"When we got off the ship we had to fill in forms asking if we'd had any cold or flu symptoms,'' she said.

"I had been feeling a bit sick so I put that down.

"Then we got a call on Monday when we were in Melbourne saying we had to be quarantined, I thought it was just me but it was also my mum and my son.

"The whole ship was being quarantined.''

The woman said when she asked authorities if she could drive home to Traralgon, she was warned to avoid the public and to stand at least a metre away from people.

"I said to her, what about all the people we saw at Sydney airport?'' she said.

The woman has been tested and cleared of having swine flu and both her mother and son are fine.

But all three have to remain quarantined at the woman's home until Monday.

"Supposedly this flu has an incubation period of about seven days ... luckily I had the week off work anyway,'' she said.

The woman said P&O Cruises had made every effort to try and minimise the spread of illness on the cruise.

"They were very conscious of it ... when we had a meal they put antibacterial gel on our hands and they were constantly cleaning the toilets and the rooms at least three times a day,'' she said.

"But I think a lot of people would have got on the boat with colds.

"A lot of people on the cruise had colds and sinus infections ... I did hear one mother in the lift talking about her son who was sick; I heard he was confined to a cabin.''