An increase in the number of people with influenza symptoms is causing concern but hospitals say they're prepared for an outbreak.
Fears over severe influenza strain A(H3N2) are growing Auckland and South Canterbury, where there have been spikes in the number of people getting consultations for flu-like symptoms, which can include fever, headache and a dry cough.
The strain, which could cause a surge in hospital admissions and deaths, has been predominant in the two regions, according to data from Environmental Science & Research (ESR).
Sentinel surveillance data, for the week ending June 10, shows a spike in influenza-like-illness consultations in Auckland (40.9 per 100,000) and South Canterbury (51.9 per 100,000).
The symptoms were the same as other strains, the A virus was was associated with "more severe outcomes'' and could be particularly dangerous for the elderly and those with an ongoing medical conditions, said National Influenza Specialist Group spokesman Lance Jennings.
Although the national consultation rate of 18.4 per 100,000 was considered below normal seasonal activity, the predominance of the H3N2 virus was a concern, Dr Jennings said.
"A major outbreak of H3N2 would cause a surge in hospital admissions and deaths. It's not too late, however, for eligible people to get a free flu vaccination which covers three strains currently in circulation in the southern hemisphere, including H3N2.''
"When you start seeing other people getting the flu it's almost too late to protect yourself. It can take up to two weeks to develop immunity from the time of vaccination. So people need to book in with their doctor or nurse today.''
The volume of travellers coming into Auckland could have had an affect on spreading the virus, he said.
In 2009 the country was hit by the swine flu (H1N1) pandemic, which continued to affect people the next year. The A virus was expected to ``fill the vacuum'' following a mild year, Dr Jennings said.
Patients with winter-related illness had been coming through the door "thick and fast'' this week, said Auckland City Hospital Emergency Department's clinical director Tim Parke.
"Influenza can be a nasty illness in a fit, healthy patient but it's pretty devastating in the elderly and other vulnerable people.'
Influenza can worsen other conditions, such as breathing or heart problems, and an estimated 400 New Zealanders die each year from it.
All hospitals had contingency plans in place should there be an outbreak if the recent rise in symptoms flows into admissions, said Dr Jennings.
In South Canterbury the number of reported cases of influenza had reduced since the report, dropping to zero in the last week.
About 940,000 New Zealanders have already had a flu vaccination this year - about the same number as at this time in 2011.
Dr Jennings urged people to protect themselves by getting the influenza vaccination. People could also wash and and dry hands frequently, stay away from those who are sick, and cover coughs and sneezes.
- HERALD ONLINE