Influenza is a viral infection. Two or three strains circulate in New Zealand between March and October each year. Typically, these are 3 main strains- one “seasonal” A strain (H3N2) and an second A strain (“often called “pandemic” A strain- such as in 2009-2011 with “swine flu”) , plus a B strain. Most strains circulate for 2 or 3 years, until a majority of the population develops immunity. Then “mutations” (new variants) arrive to replace them.

See New Zealand’s ESR influenza updates (published between April and November each year).

The annual flu vaccination contains the 3 most current Influenza strains, and is highly effective. Contact us before February each year about getting flu vaccinations.

The virus is extremely infectious, but most people who get infected by have only a mild to moderate form of the flu; however, a small proportion will get a serious infection – especially if they have pre-existing medical conditions or are pregnant.

It is also know that the faster it spreads, the larger will be the number of people becoming unwell at the same time.  This may have a major impact not just on those individuals but may overload health care services, and cause major disruptions to social and business life.  Therefore, we all must play our part in slowing its spread.


Sometimes, it can be hard to know for sure if you have Influenza, because only some will have ‘typical symptoms’. Many will have minor symptoms and some have none.  All of these people can spread the infection.

Typical infection = sudden onset of fever, chills or sweats, headache, aches and pains, and often sore throat or cough.  This group go from feeling well to feeling very unwell in the space of less than 2 hours.

If this happens to you, you usually do not need a doctor or a swab test to tell you that you have influenza. In this situation, please follow the simple guidelines listed below.

Minor symptoms = the majority of people with minor symptoms have symptoms more like a cold.  For these people, it can be very hard to know if it is influenza unless other people around have a typical infection or if is known from testing that almost all of the infections in the community are influenza.

So if you have minor symptoms and other people around you have typical influenza, then you should be more suspicious that you have a mild form of influenza and you should seek advice either by calling Healthline 0800 611 116 or your general practitioner.


if you know, or are told, that you have influenza?

  • stay at home for 7 days following the start of symptoms
  • let somebody know you are unwell because some people deteriorate unexpectedly
  • try to isolate yourself at home to reduce the chance of spread
  • follow strict hygeine rules use tissues to cough or sneeze into; put tissues immediately into a sealed container.  Wash hands regularly either with an alcohol based gel, or soap and water
  • keep well hydrated and eat small amounts of healthy foods
  • treat symptoms such as fever and runny nose or sore throats in the usual way (paracetamol/decongestants etc)
  • seek medical advice if you feel you are getting steadily worse – but remember to ring first

For further information:

New Zealand- see

International- see