Lowered immunity levels may be partly to blame for a flu sweeping the country.
In the past week, according to official figures, 404 people throughout the country saw a doctor because they were suffering from the flu or a flu-like illness. Of those, 44 were diagnosed with influenza, including 34 with this year's dominant strain: H3N2.
The Ministry of Health's health intelligence team said H3N2 has been the main strain in New Zealand for 20 years but had not previously spread widely. That could mean there has been some reduction in immunity among those not vaccinated annually.
The Ministry of Health has extended free seasonal flu jabs for those eligible until the end of August.
Last week Aucklander Lucy Janisch-Fitzgerald, a 22-year-old otherwise healthy woman, wound up on a ventilator in hospital.
Janisch-Fitzgerald spent eight nights in Auckland Hospital and had to take another week off work.
Like many people, she had no idea how bad the flu could be: "People think that it's going to pass within 24 hours, but it doesn't."
National Influenza Specialist Group spokesman Dr Lance Jennings said the most common symptoms were a sudden onset of illness, a high fever, a headache which could be severe, a dry cough, muscle aches and shivering. Bed rest was necessary and patients get severe complications such as pneumonia. The illness usually lasted 7-10 days.
Visit www.fightflu.co.nz for more information.