Very good point.
The 'Spanish' influenza may, however, have originated in March 1918 among U.S. soldiers in Kansas; about 500 men there were infected, among whom 48 were listed as having died of "pneumonia".
Those who survived the illness may have carried the disease to Europe, where in the summer and fall of 1918 over one and one-half million U.S. soldiers were sent to fight in World War One.
On September 28th, 1918 a "4th Liberty Loan Drive" parade in Philadelphia was attended by 200,000 people. Since influenza is a respiratory illness spread by breathing, within days of the parade 635 new cases of influenza were reported; and on 6 October, 289 people died.
In the midst of the epidemic the acting Surgeon General of the Army noted the unusual character of this epidemic: whereas influenza normally was a mild disease that killed only the very young and the very old, this influenza was most dangerous to people 21 to 29 years of age. This influenza took the strong and spared the weak.
Did you see NOVA last night? The family profiled had 3 who tested positive. The young man (18?) nearly died and has some permanent repercussions. The young girl (10?) recovered fully. The grandfather (80) was completely asymptomatic.