Influenza experts are urging people to be vaccinated against seasonal flu to reduce their risk of a potentially more serious double hit if they catch seasonal and swine flu together.
Because of the rapidly rising number of swine flu cases in Australia, New Zealand's public health authorities expect the virusto take hold in this country and eventually infect more than half the population.
A New Zealand woman, suspected of having swine flu, arrived in Auckland on board the Pacific Sun yesterday.
However, testing revealed she had seasonal flu and she and more than 10 quarantined close contacts were released. The woman joined the P&O cruise in Brisbane on May 27.
Around the world the number of confirmed cases of swine flu has leapt by 2000 to more than 19,000, including 117 deaths. But the disease has generally been mild in New Zealand.
The National Influenza Strategy Group said a record number of people had been vaccinated against seasonal flu this year - 840,000 doses had been distributed.
It costs $25 to $30 for a flu jab at a general practice. But the vaccination is state-funded - until June 30 - for people 65 or older and for those with chronic health problems such as heart failure, kidney disease and diabetes.
Influenza group spokesman Dr Lance Jennings said last night it was doubly important for everyone to be vaccinated this year.
"There's a multiple risk if people contract seasonal influenza and are recovering from that and are then exposed to swine influenza. They may have a double whammy and be less able to cope with it."
Increased rates of seasonal flu vaccination could also, theoretically, reduce the chances of swine flu swapping genes with seasonal flu and becoming more virulent. However, this was likely to happen regardless as many people around the world did not get vaccinated.
The Ministry of Health said New Zealand now had 11 confirmed cases of swine flu, in addition to 10 probable cases. The latest confirmed case was a passenger who arrived in Auckland from North America on Saturday on an Air New Zealand flight.
That person and their close contacts were being asked to stay home while they were treated with Tamiflu.
