Mutation fear as swine flu cases grow

Health officials say there is still no cause for concern despite a rapidly increasing swine flu tally.

The Health Ministry today confirmed there are more than 300 confirmed cases of swine flu since the outbreak began over two months ago.

"Health authorities are well-prepared in the event the outbreak becomes more severe. We had prepared for this since four years ago and our response will remain coordinated and thorough." The Ministry said in a press release today.

"We expect the numbers will continue to rise as the pandemic continues over coming months. The virus is expected to cause many more infections than are seen with seasonal or ordinary winter flu because most people have no or little immunity to it."

Of the 45 new confirmed cases, 22 are in Auckland, 10 in Wellington and nine in the Bay of Plenty.

There are 733 suspected cases and 17 probable cases nationwide.

Health authorities said that despite not testing all suspected cases, they were still watching the spread and the behaviour of the virus through the Institute for Environmental Science and Research (ESR).

MUTATION FEARED

Fears are growing that swine flu - which has killed 180 people worldwide - will become resistant to antiviral drugs after confirmation that winter flu strains here are no longer susceptible to the antiviral drug Tamiflu.

Wellington Hospital yesterday confirmed more infections, including a seriously ill teenage cancer patient.

Health Ministry officials says the actual number infected was likely to be "in the thousands" as doctors had stopped testing every patient.

A 30-year-old woman - one of six affected Wellington Hospital patients - remained critical in intensive care last night. A teenage cancer patient in the oncology ward was isolated on Friday night after being diagnosed and another patient who shared her room was also being treated with Tamiflu, along with nursing staff.

Swine flu currently responds to Tamiflu. But Environmental Science and Research virologist Sue Huang, head of the World Health Organisation national influenza centre in Upper Hutt, said scientists feared it could mutate with a Tamiflu-resistant strain. All 18 seasonal influenza type A strains tested so far this year have been Tamiflu-resistant.

"Viruses are notoriously unpredictable ... if there was mixing of the novel virus with other AH1N1 strains circulating, such as in a person infected with both strains, the novel virus could take on resistant characteristics."

The ministry is stockpiling another antiviral drug, Relenza.

The ESR laboratory, one of only five nationally equipped to test for swine flu, hoped to clear its backlog of about 200 samples last night.

MANAGING THE FLU

Meanwhile, Auckland will today follow the lead of Wellington and Christchurch and begin focussing on managing swine flu cases rather than trying to contain the virus.

And in Christchurch last night the Flu Centre extended its opening time by six hours a day to cope with the number of people referred to it with flu symptoms.

The centre, which opened on Friday, saw 79 patients on Saturday, the Canterbury District Health Board said.

FLU HITS THE PACIFIC

Meanwhile, Fiji has its first confirmed cases of swine flu.

Both men, one a 36-year-old and the other, 32, were quarantined over the weekend, Fiji Live reported.

Both patients, who are from Nadi, came into contact with infected persons while in Australia.

Samoa had its first conformed case a week ago after a visiting Australian student tested positive for swine flu.

Testing for suspected swine flu cases is carried out by ESR in New Zealand.

- Stuff.co.nz and The Dominion Post