To maintain morale, wartime censors minimized early reports of illness and mortality in Germany, the United Kingdom, France, and the United States.[10][11] Papers were free to report the epidemic's effects in neutral Spain (such as the grave illness of King Alfonso XIII).[12] These stories created a false impression of Spain as especially hard hit,[13] thereby giving rise to the pandemic's nickname, "Spanish flu".[14]
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The major troop staging and hospital camp in Étaples, France, was identified by researchers as being at the center of the Spanish flu.
https://en.wikipedia.org/wiki/Spanish_flu
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To maintain morale, wartime censors minimized early reports of illness and mortality in Germany, the United Kingdom, France, and the United States.[10][11] Papers were free to report the epidemic's effects in neutral Spain (such as the grave illness of King Alfonso XIII).[12] These stories created a false impression of Spain as especially hard hit,[13] thereby giving rise to the pandemic's nickname, "Spanish flu".[14]
...
The major troop staging and hospital camp in Étaples, France, was identified by researchers as being at the center of the Spanish flu.
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So actually the "French Flu"