Based on the descriptions I have read of influenza, I’m relatively certain I have either never had it or have had it maybe once in my adult life.
Most years I get a bad cold that lasts 5 days or so (plus some time for my sinuses to completely return to normal) and maybe a couple lesser colds. None of these are “the flu”.
I get the flu vaccine every year, but only started that around age 35 or so. I’m in my early 50’s now.
I've only had the flu once that I know of after an conference in Las Vegas about 12yrs ago, and it was the worst illness I've ever had. I went into work on day 1, immediately turned around went home, and nearly passed out going up the stairs. The next three days were a fugue of blinking and the shadows from the trees outside moving.
For anyone with unvaccinated proper influenza there should be no question of if you're going to work or not. You're not going to be capable of it. Trying to order groceries online should be highly mentally taxing.
I'd strongly recommend once someone sees a fever above 100F that they get antivirals as well and not try to suffer through it like a dumbass.
(Tangentially, compare to people who "got the worst sickness of their adult life" in late 2019 and swear they were patient zero of COVID in the US -- probably just influenza, 19/20 was a bad season before COVID hit).
“During seasonal epidemics, it is estimated that about 80% of otherwise healthy people who have a cough or sore throat have the flu.”
> During seasonal influenza epidemics, diagnosis on the basis of clinical presentation has reasonable accuracy in previously healthy young and middle-aged adults, in whom the presence of fever with either cough or sore throat is associated with influenza virus infection in ~80% of patients.
So Wikipedia doesn’t add that this statement is about the accuracy of diagnosis by a clinician, and completely ignores the important symptom of a fever.
Just prior to the statement referring to 80%, Wikipedia also states the following, with references:
> In a typical year, influenza viruses infect 5–15% of the global population
Colloquially flu is often reserved for a non-specific viral infection that makes you very unwell, but that could be a “common cold virus”, while somebody with a “cold” might be suffering from influenza!
I’m surprised that this belief still holds despite the wide exposure to higher quality information on this topic during the pandemic.
Rhinovirus, common cold coronaviruses, metapneumovirus and even RSV don't commonly cause the high fever seen in typical symptomatic influenza cases--which is what the influenza vaccine is seeking to avoid.
And the whole point is that vaccination will help to prevent a symptomatic infection typically characterized by ~103F fever for up to 3 days with one of those asymptomatic infections that you mention.
And the problem is that most adults may go years or even decades between those severe enough flu infections. They're mostly likely just catching colds. Maybe they caught a flu strain and their adaptive or innate immune system fought it off so they really did have "24 hour flu". But the point is that those very mild respiratory infections are not characteristic of a typical symptomatic influenza presentation which can be prevented by the vaccine. People become complacent talking about those symptoms as being typical of influenza, while typical symptomatic presentation of influenza is much worse.
And even if you want to go down the rabbit hold of arguing PCR this or that and maybe there's a wild amount of asymptomatic influenza infections every year -- it doesn't really matter -- the point is the severity of the infection on the higher end of the distribution. And rhinoviruses really do lack that level of severity because they don't carry the same disease burden and don't kill as many people.
But once you arbitrarily declare somebody didn’t have flu if they weren’t sick for three or more days, or didn’t get a high enough fever, well then I don’t think that’s valid either in common usage or scientifically.
Since you brought up people misusing terms, I think that’s a pretty valid response.
> typically characterised by
What are you basing this on? I have only found estimates of asymptomatic infection, but do you have any studies that performed a random sample of the population looking at disease severity by positive PCR?
Covid was a much more severe illness with very little endemic immunity and we still saw dramatic variation in outcome. It seems to be estimated that a third of influenza infections are asymptomatic - do you propose that the distribution is entirely bimodal and that everyone else had severe symptoms? This seems implausible given the broad (and highly differentiated by prior variant) level of population immunity.
The only studies I could find (with an admittedly cursory search) look at people already suffering from ILI and testing the likelihood that the ILI is influenza, which does not tell you what proportion of people experience mild symptoms with influenza infection. It does however tell you that many of these people are not suffering from influenza, but would have likely said they had “flu” and met your criteria.
My point therefore is that “flu” doesn’t mean influenza, since there’s no common definition that is either sufficient or necessary to correctly identify an influenza infection, and we do not require a PCR test to use the term. It therefore means a severe non-specific viral illness, or perhaps an “influenza like illness”
It also means criticising people for using the term for a mild illness is probably fair, but not because it doesn’t meet the criteria of being influenza, and I really wish people would stop using this kind of argumentation about it, as though they have any idea what a specific influenza infection looks like.
This is one of a class of problem I've identified as "stuff i learned in my childhood that is simply wrong".
For some reason, I grew up with the impression that vomiting and/or GI issues could be the flu, or the 24 hour flu. I'm not entirely sure how respiratory viruses with fevers became confused in such a manner.