"Thankfully, there is still very little actual influenza circulating in the community, although we are seeing other respiratory viral infections, including common colds," the NISG virologist said. "We know people often mistake them for influenza. They may have some similar symptoms but they're not the same disease."
Symptoms of the flu included a sudden onset of illness, high fever, headache and a dry cough, he said. The illness usually lasted between seven and 10 days.
Dry winter air and chilly temperatures often resulted in increased cases of flu, Dr Jennings said.
"Studies have shown that human influenza viruses generally can survive on hard surfaces between two and eight hours, so that's why we stress the importance of good hand hygiene."
"Keeping your distance if you're sneezing or coughing" is also important, he said.
People with underlying medical conditions risked serious illness, hospitalisation and even death if they contracted the flu, Dr Jennings warned, and those at greatest risk from flu complications should be immunised as soon as possible.
Free immunisations were available to a large number of New Zealanders - including those aged over 65, people suffering from long-term health conditions such as asthma or diabetes and pregnant women - until the end of July.
About 1.2 million people have already received the vaccination, which poses no risk of causing the actual flu, Dr Jennings said.
Flu
- Sudden onset of illness, lasting 7-10 days
- High fever
- Headache
- Dry cough
- Muscle aches
- Shivering
- Can suffer severe implications like pneumonia
Cold
- Mild illness, fever, headache
- Coughing can occur
- Runny nose
Source: National Influenza Specialist Group
