I reckon you probably weren't thinking of Italy when you asked; but, here it goes anyways.

On October 18^th 1918 the Italian Ministry of Interior produced the following circular in the matter of public health, concerning especially the sanitary practices within public offices.

special personnel is to be tasked with the cleaning of the spaces, systematic washing of the [windows and doors] frames, of all points subject to frequent contact [with the people] […] Furthermore materials and instruments of common use [for cleaning] have to be provided or if necessary [their number] increased […] Collected waste has to be stored in appropriate recipients, to be promptly removed [from the common spaces].

It is also necessary that all [public work] spaces, and especially those frequented by the public are provided with ample supply of spittoons, preferably with quick lime in blocks [as a disinfectant] [and in addition] to provide each desk with a [wet finger pad] in order to avoid, in handling papers, the frequent habit of bringing someone's fingers to their mouth.

[By means of those precautions] it is possible to avoid or vastly reduce the danger of infections within working spaces.

As you can see, the circular dealt with two - at the time - widespread habits of the Italian population: clearing one's throat and spitting on the ground (inside public spaces as well), or (for the educated folk) inside a piece of cloth, and licking the tips of one's fingers in order to better handle papers and notes.

It is difficult to say conclusively that the relative decline in popularity of those practices - especially the first one, which is almost universally frowned upon, even outside - is due exclusively to the influence of the, well, influenza. What is certain is that, given the absence of any effective treatment and the limited impact of prevention measures, most of the limited "information campaigns" promoted on the press focused on the need for "cleanliness" and "disinfection". The use of moutwash was recommended, and "don't spit" signs were posted outside shop windows, restaurants and bars; people were invited to wash their hands as often as possible. Separation of the infirms from the other members of the familiy was also recommended.

You can easily imagine how these measures were difficult to follow for those people who lived in cramped houses, used to warm one room during winter (if at all, given the scarcity of firewood), and without running water. As a consequence, many of those "unsanitary" practices came to be connected with poverty, confirming the traditional identification of filthiness and ignorance with disease. Avoiding them, even when the health motivations had ceased to exist, continued to be perceived as a form of social distinction.

A specific accent on hygiene was present on the press as well - here a short list of recommendation published on the Avanti! on October 11^th 1918

The epidemics

Rules of personal hygiene

With the ongoing epidemics we offer some advice for personal hygiene suggested by a known practitioner. […]

1.o Do not change your life habits. Preventive practices involving ingestion of remedies, tablets or other substances are useless. Similarly useless is the use of purges, if the organism is regular. [...] 2.o Keep yourself clean. Wash your hands frequently and take a bath, without using disinfectants. Soap and water are the best detergents for the human body. Wash your mouth using a toothbrush […] If possible, do not bring home your work clothes […] 3.o Keep your home clean […] Kitchen and toilet the cleanest. […] 4.o Eat food, as much as possible, plain and cooked. Boil milk. Wash accurately fruit and vegetables. Avoid excesses with food and drinks. Heavy drinkers are more susceptible to infectious diseases. 5.o Do not, unless necessary, visit the ill, the recovering or the dead. Avoid crowded spaces [...] 6.o Avoid air flows when sweaty [...] 7.o In the work places, workshops, and offices, everyone should contribute to the cleaning and aeration of the common spaces […] Do not spit on the ground. […] 8.o Do not waste your money with the purchase of disinfectants, especially the odorous ones, which have no actual disinfection power [this point was likely due to a desire to mitigate the mounting popular demand for, actually useless, disinfection of public spaces with phenol and similar compounds, at significant cost for the city administration] […] if necessary, for the disinfection of common spaces use a solution of sublimate [Mercury Chloride] five per one thousand, keeping in mind that sublimate is a powerful poison […] 9.o Those who experience fatigue, sore throat, general malaise, chills, should commit to bed immediately [...] and contact their physician […] 10.o During illness it is recommended to keep the bed chamber well aerated day and night. Small clothes should be kept in a pail with a solution of sublimate two per one thousand, to be kept in the same room as the afflicted person. […] Do not let relatives or friends in to visit […]

For reference: Tognotti, E. - La “Spagnola” in Italia

Mortara, G. – La salute pubblica in Italia durante e dopo la guerra

Cosmacini, G. – Storia della medicina e della sanità in Italia

So. This is NOT going to be the answer that you expect. Or want. Or one that is even useful.

But I'm going to throw it in here anyway, because it is part of what "real history" is. Which is: not conforming to expectations or desires. Because doing real history means--in part--finding out that something you thought would be crucial is just not as vivid, prevalent, or important as you imagined.

Sometimes, the silences themselves speak. (but what is it that the silences are saying????)

I'm a historian of Germany, and my current book project works on the intersection of political history, commercial history, and cultural history during and after the First World War.

The 1918-1919 transition is BIG in my primary research.

So, I've read hundreds of journals--and by hundreds of journals, I mean, every issue of hundreds of journals. (so, to be clear, we're talking, 100,000+ pages of text that I've at least skimmed, and, if interesting-looking, read closely.) I've read government documents in the multiple thousands. I've seen tens of thousands of advertisements from 1918. I feel like I have as solid a glimpse into German life in 1918/1919 as anyone could, without having lived through it.

And what have I seen of the pandemic ("Spanische Grippe", or Spanish flu, as it's called in Germany)?

nothing.

Not a word. Not a single government document. Not a single advertisement. Not a single hand-wringing newspaper editorial, "what are we going to DO about this flu???"" (other than a noticiable uptick in advertisements for coffins... which seems apros pos.)

But here's what we know. We KNOW that 270,000 or so Germans died from influenza pandemic.

It was a BIG deal, in terms of mortality.

Sure, not as big a deal as trench warfare...(until November, 1918). But a bigger deal than starvation from the Allies' "hunger blockade"--as it was called in Germany--namely, the blockade of foodstuffs into Germany. And the "Hungerblockade" and the turnip winter (of 1917-1918) loom HUGE in my sources. Everyone talks about that.

But NO ONE is talking about the influenza.

So what does this mean??

What does it mean, when hundreds and hundreds of thousands of people could die, without any significant commentary in the sources (governmental, military, commercial, cultural) that i've been able to see?

I have no idea.

(!)

Truly, I have no idea.

My supposition is that other issues were SO pressing: the brutal losses in war; the painful hunger experienced by everyone; the bitterness around the issue of war-profiteering (and the fact that the upper classes did not experience the hunger and deprivation of everyone else); the political instability; the Revolution (!!!) which meant a new beginning for some, and a crushing Loss for others; the Betrayal (by the new Republic) of the sacrifices of the men in uniform (as it was perceived and/or declared) by signing the treaty of Versailles; the new optimism of peace, and possibility for a new world defined by the end of war and by the promise of peaceful competition (in the commercial realm); etc. etc. (I could go on for paragraphs and paragraphs here. A lot was going on in 1918/1919 in Germany. A lot. And it was all highly politicized, and the experience of what was actually happening then was so dependent on one's individual circumstances..) But--I need to emphasize--this is guesswork. Not a sourced argument.

The fact of the matter is, it seems (by my research--which is NOT comprehensive or exhaustive by any means) that the massive death of the flu of 1918, at least in Germany, wasn't really big deal. It was not a public or cultural issue. (too much other pain, suffering, upheaval, despair, and promise was circulating...?? I don't know.)

I'm not sure how to offer citations for this: I'll just say, the archives I've been focusing on are military archives (in the Bundesarchiv in Freiburg); political archives (in the Bundesarchiv in Lichterfelder); and in commercial and/or print-media publications (too numerous to list) found in libraries throughout Germany, but especially the Staatsbibliothek Berlin.

Hope this was interesting, helpful, or if none of these.. just provocatively head-scratching.