The number of confirmed cases of influenza A/H1N1 in New Zealand rose to 86 on Monday, an increase of 15 from Sunday, said Health Minister Tony Ryall.

Ryall told a press conference in Wellington that the number was expected to rise and the Ministry of Health was going to step up its public information campaign about flu prevention.

"What we're seeing around the world is that there's a rapid transfer in young people," he said. "The strategy remains containment. We want to delay the major impact of swine flu beyond the normal winter cycle."

Ryall said there were normally about 31,000 hospital admissions a month during winter and health officials thought there could be another 4000.

The Ministry of Health has moved up its national pandemic planning to level 6.2 - the last phase before what it calls "Code Red", in which the virus is not contained and widespread.

The health minister said there was no cause for alarm. He said more cases can be expected now that the disease is being transmitted through the community, but the virus is mild and most people infected have been able to manage it themselves without medication - and have recovered quickly.

Ryall said the health authorities were trying to delay its spread to reduce the stress on emergency departments and clinics, already under pressure with seasonal flu.

Specialist testing centers have been set up at hospitals in Wellington and Lower Hutt for people who public health officials refer to be swabbed for the virus to keep them away from regular hospital patients.

It is anticipated the influenza A/H1N1 may have another two months to run before its potency begins to fade in New Zealand.

A small Catholic Auckland primary schools has become the first school to close its doors to all students after a Year 5 pupil was confirmed as having the flu virus.

Carmel Bullot, principal of St Patrick's in Panmure, said she was contacted on Sunday by Auckland regional health authorities, though the decision to close was made late on Monday afternoon.

Bullot said 36 of the 145 children on the roll were absent on Monday, and four more were sent home before lunch.

Burnside High School in Christchurch and Auckland's Westlake Girls' High School have imposed partial quarantine after a student at each school contracted the virus.

Nearly a quarter of Westlake students has been ordered by health officials to stay home this week after a Year?12?girl contracted the virus. Other people with symptoms will also be treated with the drug Tamiflu.

Burnside principal Ron Noordijk said 47 Year 9 pupils and five teachers are being treated with Tamiflu and kept in home isolation until Wednesday.

The health minister said in Australia school closures have slowed the spread of the disease and he expects more schools to adopt the same measures if need be.

The Council of Trade Unions said workplaces need to boost communication with workers about influenza A/H1N1, as concerns about the virus escalate.

Health officials were warning the number of cases could grow quickly, now that the H1N1 virus is spreading in the community and has been found in people not linked to overseas travel.

(Xinhua News Agency June 15, 2009)