You are kinda correct. On relating to int’l events...Mar 1919, is when it gets ‘re-used’.
Originally, it was developed by the French...1821. French used the idea (30k troops in the mix) along the French/Spanish border...originally to prevent Yellow Fever coming from Spain into France. This was a fake agenda...real purpose was to prevent Spanish propaganda/fake agenda...from getting into France (if the story from French sources is true).
Even then, you had to worry about fake news. (Hard to believe fake news from Spain...out-bested....fake news from France).
I was citing its first use in an explicitly military/political (rather than "hygienic") sense.
But thanks for your contribution to the conversation.
Regards,