The 1918 flu pandemic was an influenza pandemic between 1918 and 1920 caused by an unusually severe and deadly strain of the subtype H1N1 of the species Influenza A virus. By far the most destructive influenza pandemic in history, it killed some 50 million to 100 million people worldwide (2.5 – 5% of the human population) in just 18 months, dwarfing the simultaneous bloodshed due to World War I. Furthermore, many of its victims were healthy young adults, in contrast to most influenza outbreaks which predominantly affect juvenile, elderly, or otherwise weakened patients.
Despite not having originated in Spain, the Allies of World War I came to call it the Spanish Flu. This was mainly because the pandemic received greater press attention in Spain than in the rest of the world, as Spain was not involved in the war and had not imposed wartime censorship. (More...)