Hong Kong's human swine flu tally has reached 104 while a Wan Chai secondary school will suspend classes after 12 new cases were confirmed today, the Centre for Health Protection says.

Of the new cases, four patients - a 15-year-old girl, a 10-month-old baby girl and two boys aged six and eight - are regarded as local sporadic cases, as they had no travel history nor apparent links or contacts with any confirmed cases.

The 15-year-old lives at Shun Lee Disciplined Services Quarters, Kwun Tong, and is a Form Four student in Tang Shiu Kin Victoria Government Secondary School in Wan Chai. She became ill on June 12, but sat for a school internal examination with about 200 students on the same day.

The school will suspend classes from tomorrow until June 29; examinations are slated to resume on June 30. The school will inform parents and students and post notices on its intranet.

The baby girl lives in Yau Tong, and developed fever and cough on June 8. She sought treatment at a hospital emergency unit and is stable. Her parents had no travel history.

The six-year-old lives in Tsuen Wan and studies in Cannan Kindergarten, Kowloon Tong. He had the onset of flu symptoms on June 13 and sought treatment at a designated flu clinic in Shau Kei Wan. His family members did not have any symptoms.

The eight-year-old is a Po Leung Kuk Fung Ching Memorial Primary School student who lives in Tseung Kwan O. He came down with flu yesterday.

The remaining six cases are imported - two from Thailand, two from the US and two from Canada. Another case involves a younger brother of a case imported earlier from Thailand.

Another secondary one student from St Paul's Convent School has been confirmed as a swine flu case, bringing the total number of cases relating to the school to 20. 

Centre Controller Thomas Tsang said whether a suspension of all secondary schools is required will depend on the centre's investigation of the 15-year-old case tonight, including whether there are other students who are ill with flu, too.

He noted the confirmation of flu among the two young boys shows the class suspension since June 12 is timely, as there could have been a wider disease spread.

Believing the virus has been established in different districts, including the New Territories, he expected a daily double-digit growth will continue and more cases will come up in the next one to two weeks.

Dr Tsang said the health authorities will put less emphasis on contact tracing and comprehensive surveillance in view of the community transmission. They will monitor the patronage of the designated flu clinics and see if more are needed.

The 104 cases involve 40 men and 64 women, aged 10 months to 56. About three-fourths were imported, including from the US and Canada in the initial stage, and Europe, Southeast Asia  and the Philippines, South Korea and Australia afterwards.

Most cases were mild with fever, cough and runny nose, similar to the situation of a seasonal flu. The patients recovered after several days, and none required intensive care treatment or developed lung infections. There have been no fatal cases.