For those who love a good multiple of 1,000, or enjoy drooling over the passing of a historical threshold, yesterday was such a day for influenza (flu) counts in Australia. 2019 was Australia’s biggest confirmed flu count on record
Laboratory confirmed flu notifications in 2019 just reached 252,142, surpassing the 2017 total of 251,163. Australia’s biggest confirmed flu count on record. Yay?
This hasn’t been a severe or even moderately severe year though. Despite the huge numbers (which can be influenced by things other than actually change numbers of infection), the big burden on hospital beds (which may be impacted by higher, media-driven numbers of short stays) and the large numbers of residential care facility outbreaks (which could simply be a result of us becoming better at recording these), the mainstay of what defines a severe season, death and intensive care admissions suggest a low severity season. Which is good news.
However, I think we need a wider discussion about “severity”. I personally feel that this messaging is out of touch with the community’s expectations. Something that is often a problem in flu’ville.
Thanks very much, A/H3N2
In yet another year of A/H3N2-dominated cough and fever, lab testing and media-driven healthcare-seeking behaviour have been front-of-mind for those looking for ways to describe these big flu seasons. That is, ways that don’t involve looking closely at efficiently transmitting, constantly mutating, highly effective respiratory virus variants. Through, ya know, virology and stuff.
The season – early though it was – has peaked, but the decline in positivity is slow. And this is despite the media kinda cooling on the whole flu thing.
Also remember, these numbers are coming from a long way up, so “peaked” just means cases have stopped rising month on month – not that the season is over and done with. In fact, there have been plenty of jurisdictions showing signs of a slight bump up in the past 2 weeks.
Unfortunately, the national fortnightly flu report seems to have gone missing in action, and now related websites have gone offline. So we’ll have to wait a bit to see the national picture.
In the meantime – feel free to check out my twitter @MackayIM timeline for the latest cobbled together numbers. I keep the latest info pinned to the top. At least for until things slow down some more.
What of the North?
A brief whip around the US and UK hasn’t found any signs of a 7-month early rise above the maximum baseline levels (I choose a worst-case threshold rather than an average) of flu notifications for the past 20 years; as Australia saw. So at least on one count the north is not “following Australia” in its flu patterns.
It really just remains to be seen what will take hold and dominate in the north’s 2019/20 flu season.
Get your vaccine when it becomes available.
If your vaccine is delayed in 2019, there’s also no real indication yet that this will influence the size of the season. If the north begins it season with viruses that are the same as the vaccine – get vaccinated when you can, and you’ll have done all that you can. The vaccine should still arrive well before the normal peak season.
If the season kicks off with a virus or two that is significantly different from the vaccine (antigenically speaking), then vaccine delay won’t be the biggest concern, but still get the shot because it has more than a single virus in it!
Side-eye to you northerners
Just on this topic, having spent a good few weeks looking into flu genome sequences from the GISAID database – it’s become more clear to me (I’m still learning new things every day, even since this post) that a lot of what Australia has been hit with – that is, the more recent flu viruses circulating around the end of last year that added into our pre-existing flu ecosystem – have lots of similarities to recent flu viruses from the US, Europe and China.
It’s almost like Australia was getting seeded with viruses via infected travellers from the north (it’s a much more complex story than that, of course).
Those of you who read my recent post Which is the inFLUencing hemisphere north, south or neither, won’t be at all surprised by that. Those of you living by the teachings of some bloke somewhere in the past at a medical school far far away; read that post and it’s linked papers.
Meanwhile, threshold droolers can paddle about in the knowledge that 2019 is now Australia’s biggest confirmed flu count on record.
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It seems that many things are involved in human host immune response to flu viruses, notably the distance between circulating strains from its ancestors (a sort of ADE but different), the climate (extreme weather might play a role in disturbing human health in general), the air pollution (that increase in very hot summers), the overall reactivity of public health system, vaccination coverage rate, for example. Europe has experienced one of the hottest summer in more than 130 years (France recorded 46°C in July heatwave, Cambridge (UK), 38°C, many German, Dutch cities broke century-old extremes). The impact on human health remains unknown and the mortality statistics will not be available for months, even though spikes in excess deaths have been reported by some of affected countries. Flu remains almost unpredictable, but it is the entire situation that is staggeringly difficult to manage, taking into account the complete, disastrous unpreparedness of public services across the continent.