Wednesday, 12 March 2014

Influenza in Queensland, Australia: 24-Feb-2014:03-Mar-2014.

Image adapted from Geoscience Australia,

The Australian Government.

Autumn is upon us as the temperatures drop and we've had several days of showery weather in Brisbane.

The Courier mail (and my local radio) media note that "swine flu" (H1N1pdm09 presumably) cases are dominating across Queensland in what may be an early flu season; 85% of notifications are influenza A virus subtypes, and "most" are the "H1N1 swine flu strain". That's the influenza A virus subtype which the northern hemisphere has been battling.


In the previous week's Queensland Health Statewide Communicable Disease Surveillance Report the higher than average number of influenza notification was apparent (unfortunately they don't carry subtyping data).


See my previous post on this uptick in 24-January ([2]; Summer down here). 

By higher, I mean that that there have been 2.4X more notifications in Queensland (840 year to date based on onset date; 85 cases in this reporting week) than the mean number over the past 5-years (the mean for the time period spanning 24-Feb to 02-Mar in the previous 5-year period is 348.8). In fact Queensland seems to be leading the pack for flu notifications this year to date.

This time in past years we have seen these notifications..
  • 840 case notifications in 2014
  • 516 cases by this time in 2013
  • 233 cases by this time in 2012
  • 820 cases by this time in 2011
  • 104 cases by this time in 2010
  • 71 cases by this time in 2009
...highlighting that there have been other large years, but also much smaller (testing bias perhaps?) tallies in other years.

Keeping in mind that these are total numbers, not proportions of samples tested. Presumably this is the basis for the media comments of an "early flue season". Cairns, Gold Coast, Logan and Moreton Bay public health unit areas are the source of notifications and it seems the more recent data add Townsville and Cape York as hotspots.

I guess the next publicly released QHSCDS Report will have these updated total numbers in it so stay tuned. 


At the end of the 2013 flu season, H1N1pdm09 comprised just 15% of all notifications (although most Flu As were untyped), <1% in 2012 [4]. Queensland followed New South Wales and Victoria in total laboratory-confirmed notifications for 2013 [4]. 2013 was a late-starting, shorter flu season compared to 2011 and 2012 [4].

Whatever the small details however - get that flu shot - it will be available from next week. An advertising campaign is about to kick off for flu vaccination but in the meantime have a chat with your GP about flu vaccination options. It really is worth preventing the severe disease, and sometimes fatal disease, that can come along with an influenza infection. Not just for you, but for your children, those around you who are pregnant, your partners and parents as well as for the wider community. 


This is one of the relatively few diseases we can attack with just a simple jab.


References...

  1. Queensland Health Statewide Communicable Disease Surveillance Report 3-Mar-2014
    http://www.health.qld.gov.au/ph/documents/cdb/weeklyrprt-140303.pdf
  2. Influenza in Queensland, Australia...
    http://virologydownunder.blogspot.com.au/2014/01/influenza-in-queensalnd-austraia.html
  3. Up to 85 per cent of current Queensland flu notifications are H1N1 swine flu
    http://www.couriermail.com.au/news/queensland/up-to-85-per-cent-of-current-queensland-flu-notifications-are-h1n1-swine-flu/story-fnihsrf2-1226851854384?from=public_rss
  4. Australian influenza report 2013 - 28 September to 11 October 2013 (#09/2013)
    https://www.health.gov.au/internet/main/publishing.nsf/Content/cda-surveil-ozflu-flucurr.htm