Pandemic
Spanish Flu
Influenza A H1N1
75.0M
estimated deaths
Period
1918–1920
Origin
United States (Kansas)
Death range
50.0M–100.0M
Infected
500.0M
Overview
The 1918 Spanish Flu was the most severe pandemic in modern history. Unlike typical flu, it disproportionately killed young healthy adults (ages 20–40), likely due to a cytokine storm immune response. It infected about 500 million people worldwide — one-third of the global population — and killed an estimated 50–100 million. It spread rapidly through WWI troop movements and overcrowded conditions.
Historical Timeline
1918First wave — spring
1918Second wave — fall (deadliest)
1919Third wave
1920Pandemic ends
Symptoms
Rapid pneumonia onset
Cyanosis (blue skin)
Hemorrhagic complications
High fever
Extreme fatigue
Affected Regions
USA
UK
France (trenches)
Spain
India
South America
South Africa
Sources & References
Compare Spanish Flu with other events
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