https://www.ncbi.nlm.nih.gov/pmc/articles/PMC340389/ Historians and epidemiologists have previously ignored Haskell most likely because his report was not published until April and it referred to deaths on March 30, after influenza outbreaks elsewhere. In actuality, by then the county was free of influenza. Haskell County, Kansas, is the first recorded instance anywhere in the world of an outbreak of influenza so unusual that a physician warned public health officials. It remains the first recorded instance suggesting that a new virus was adapting, violently, to man.
https://www.discovermagazine.com/health/10-misconceptions-about-the-1918-flu-the-greatest-pandemic-in-history
In fact, the geographic origin of the flu is debated to this day, though hypotheses have suggested East Asia, Europe and even Kansas.
https://www.nationalgeographic.com/news/2014/1/140123-spanish-flu-1918-china-origins-pandemic-science-health/
1918 Flu Pandemic That Killed 50 Million Originated in China, Historians Say