And finally, yet another quote from the same report:
The highest number of ILI related deaths (94) in New Zealand was recorded in 1996 during an A(H3N2) epidemic. The highest number of hospitalisations (591) was recorded in 2003 during an A(H3N2) predominant season.
During the 2008 winter season, 3 945 consultations for influenza-like illness (ILI) were reported from a national sentinel network of 85 general practices. It is estimated that ILI resulting in a visit to a general practitioner affected over 47 697 New Zealanders (1.2% of total population) during the season, compared with an estimated 32 771 in 2007.
As of 2100 yesterday (1 July, 2009) New Zealand had 711 confirmed cases of swine flu (H1N1 Influenza A). This was 124 more cases than the previous reporting to the WHO only two days earlier.
This represent a rise in confirmed cases of 10% per day, or nearly double the number in a week (~96% increase).
If the number infected were to continue rising at this rate then in approximately 3 months every single person in New Zealand (4.18 million people) would have caught it (exponential growth is spooky like that)!
Thankfully, disease spread statistics are not like that – the European CDC estimates are that ~25% of a population will contract a novel strain of influenza (such as swine flu). The rate of increase worldwide is only ~4% per day (40% per week). However, it does give pause for sober reflection.
At present the mortality of swine flu is ~4 deaths per 1000 who get it. Again, using the NZ population as a model, if we all get it then ~16000 people will die from it. If only a quarter, then 4000 people. And that doesn't take into account the disruption from morbidity – people off sick from work and the like.
That ends the doom and gloom sermon for the day…
New Zealand Ministry of Health definition of Influenza-like Illness (ILI):
Influenza-like illness: (i) history of fever, chills, and sweating or clinically documented fever ?38 °C, plus (ii) cough or sore throat.
