New Zealand health officials say all travellers, particularly school children returning from Melbourne, should watch out for signs of flu.
The advice comes as cases of swine flu rise steeply in Australia and health officials brace for community spread of the virus in New Zealand.
Health Minister Tony Ryall says there are more than 650 cases of swine flu in Australia, mostly in Melbourne.
An update to New Zealand schools on Thursday says parents should keep children with flu symptoms at home and call their doctor whether they have travelled to affected areas or not.
Meanwhile, another New Zealand case of swine flu, also known as H1N1, was confirmed on Thursday.
The person arrived in Auckland from North America on Sunday, bringing the total number of confirmed cases to 11.
More cases 'inevitable'
Virologist Dr Lance Jennings says it is inevitable the number of swine flu cases will rise following the rapid increase in Australia, where more than 500 people are confirmed to have had the virus.
Rapid person-to-person spread of the virus is happening in Australia, he says, and it is likely travellers will bring the virus to New Zealand.
Dr Jennings says excellent border control and other measures have bought New Zealand valuable time in which to prepare.
Dr Jennings and Health Ministry officials say the virus is generally mild and there is no need for alarm.
The Ministry of Health is to launch an awareness campaign on Saturday, stressing the need for those who feel ill to stay at home and not to cough and sneeze over others.
NZ woman cleared
Auckland health authorities say a New Zealand passenger on board the P&O cruise ship Pacific Sun, which berthed in Auckland on Thursday morning, does not have swine flu.
Tests taken on the ship indicated the woman had influenza A, and final test results have cleared her of having the swine flu strain.
The clinical director of the Auckland Regional Public Health Service, Julia Peters, says the woman and others who had been in close contact with her are no longer in isolation.
Most of the 1,700 passengers who disembarked from the Pacific Sun were unaware of the activity over the suspected swine flu case.
Public health officials say the New Zealand woman boarded the ship in Brisbane last week.
Other cruise ship passengers tested
Passengers on board two cruise ships in Australia were quarantined recently after a swine flu scare.
Last week, three passengers on the Pacific Dawn tested positive for the virus, and other passengers were checked before they were allowed to depart from the ship.
On 23 May, passengers onboard its sister ship, Dawn Princess, were quarantined for five hours before being allowed to disembark in Sydney.
The ship was then caught up in a second swine flu scare, with New Caledonian authorities ordering vessel to anchor offshore while 16 people with flu-like symptoms were tested.
The tests returned negative results and the passengers will be allowed to disembark when the ship arrives in Sydney on Friday.
