Pandemic plan outlines methods to battle virus

An elderly lady wears a white protective face mask upon arrival at the Auckland International Airport. Photo / Greg Bowker

Once a virus is able to easily pass between people and survive ongoing transmission, the World Health Organisation will lift its alert to "pandemic".

The first case of human-to-human transmission outside Mexico was discovered in Spain and prompted World Health Organisation officials to increase the international threat level.

One of the suspected New Zealand cases is believed to have passed between family members on the flight to New Zealand.

Steve Brazier, the Ministry of Health national co-ordinator for emergency planning, said the person had travelled in Mexico but shown no symptoms while there.

It was only on the flight home that symptoms emerged and the person may have caught the virus on the aircraft returning to New Zealand.

Brazier is among those overseeing the New Zealand Influenza Pandemic Action Plan, which has laid out guiding principles for those involved in battling the virus.

It lays out a series of scenarios to match the stage at which a virus spreads, and gives officials a blueprint to operate by.

He said the plan had been designed to cope with bird flu. The swine flu virus was "different in terms of the pattern of outbreak we planned it around".

Where bird flu was expected to come from Asia and be "slow moving", swine flu "popped into life almost out of nowhere. It's a very unusual spread. Very fast and obviously very contagious."

The pandemic plan shows a staged response to a virus outbreak that extends to what Brazier calls "draconian and dramatic" measures such as closing schools, isolating the North and South Islands and even shutting New Zealand's borders.

Brazier said those "key decisions" were put before government ministers.

One of those "key decisions" that shows an escalation in response to the virus is screening passengers leaving New Zealand.

Niue has asked that passengers on the once-a-week flight to the tiny Pacific Island would be screened as they left New Zealand.

The plan sets out various stages depending on the spread of the virus - keep it out, stamp it out and finally manage it, if the virus was not contained.

Brazier said the country was operating on a mix of the latter two stages.

The job was made less complicated, he said, with the Rangitoto College group being an easily identifiable cluster that was easy to confine.

"The school kids must have encountered a super-spreader. Some people are particularly prone to spreading diseases. Or they were in an environment where someone sneezed over the whole lot of them. We're not seeing a pattern of infection from strangers."

He estimated that controls had so far identified 90 per cent of those who had entered the country with swine flu. "There is no great outbreak of swine flu. If people were going to be sick, they would be sick by now."

However, he said it was too early to know how the virus would develop.

"Is this a nice relatively easy-going disease that doesn't kill people [outside Mexico] - which is what seems to be the case - or is it a nasty disease that has mutated from a nice disease and spread around the world. We just don't know."

Julia Peters, clinical director at the Auckland Regional Public Health Service, said staff were operating at capacity in dealing with swine flu. Any escalation would trigger the next phase of the plan, and lead to staff being drafted in from other agencies.

"The public needs to know that health workers are working incredibly hard to manage the situation on their behalf."