With 10 more cases of swine flu detected yesterday, parents were urged to take extra precautions by incident controller Dr Helen McArdle.

There are now 13 confirmed cases in the North-West, seven in the North and five in the South, bringing the total to 26.

"We have been able to contain the number of people with human swine flu to a relatively small number, however the return of children to school presents us with a new challenge," she said.

"National and international evidence shows swine flu spreads rapidly within the school system."

The Department of Health and Human Services has warned the number of confirmed cases is a cumulative figure and not an indication of the number of active cases.

Education, corporate services deputy director Greg Glass said parents should keep their children at home if they were showing flu symptoms or had returned from areas affected by the human swine flu.

"We recognise that keeping students home from school may be inconvenient for some parents but we urge their co- operation at this time," he said.

At the Launceston Airport and Aurora Stadium, during Hawthorn's clash against Brisbane, health authorities were taking every precaution, handing out health alert cards.

Jodi Williams was paying attention to the warnings after returning from Melbourne with her children Sam, 13 and Alyce, 10, yesterday.

Mrs Williams, a teacher from Wynyard, said that she would be keeping her children at home for seven days, although they were not sick.

She received a letter from the education department informing her this was the protocol.

"It is strange that as a teacher I am able to go back and teach and my children have to stay at home," she said.

New reports from health authorities have said parents will now be asked to keep their children home for five days.

Dr McArdle said that if a student was detected with swine flu, the school would not automatically be closed, instead action would be determined on a case-by-case basis with public health authorities considering all the circumstances.

Quarantine measures do not apply to year 11 and 12 students, or Tasmanian Academy and Tasmanian Polytechnic students, as they are expected to follow hygiene procedures.