structural:expansion, information:classification
Descriptive names

Outbreaks of influenza-like illness were documented in 1916–17 at British military hospitals in Étaples, France, and just across the English Channel at Aldershot, England. Clinical indications in common with the 1918 pandemic included rapid symptom progression to a "dusky" heliotrope cyanosis of the face. This characteristic blue-violet cyanosis in expiring patients led to the name 'purple death'.

The Aldershot physicians later wrote in The Lancet, "the influenza pneumococcal purulent bronchitis we and others described in 1916 and 1917 is fundamentally the same condition as the influenza of this present pandemic." This " purulent bronchitis " is not yet linked to the same A/H1N1 virus, but it may be a precursor.

In 1918, ' epidemic influenza ' (Italian: influenza, influence), also known at the time as 'the grip' (French: la grippe, grasp), appeared in Kansas in the U.S. during late spring, and early reports from Spain began appearing on 21 May. Reports from both places called it 'three-day fever' (fiebre de los tres días).