Not my specialization, but from what I understand the rich went hypochondriac. If someone coughed they were fired. They didn't know how germs worked at the time so a lot of older methods were used that probably spread it further. Hospitals were not trusted because they didn't really understand cleaning instruments yet, or even how to treat things correctly.

So, they would group anyone they thought had the flu in the same building and wait for them to die while the nurses treated them without masks. Meanwhile, the rest of the world was busier with empires trying to expand and not being able to without taking out others. World War I. A small scandal in finances happened during this time, but it's barely remembered today. It was a lot like COVID I guess.