A specific type of acute viral respiratory infection, with one virus (many strains) and a short, nasty stay. A few thousand people die from it every year, but humans alive at present have almost universal partial resistance. It was not so during WWI, when it first began to spread. It was variously called Spanish Influenza, La Grippe, and Influenza (Italian for Influence)...everyone blamed some other country for it. The Turks and Armenians took a break from mutual mutilation and blamed it on each other, since it was killing as many people as the 1,000,000 fatalities THAT bit of genocide fostered. It ran across the world like some Bergmanesque horseman, and killed at least 20 million people before it petered out around 1925. The villages of Northern New Mexico, filled with grim and genetically toughened Spanish settlers, survivors of terrible weather, 300 years of isolation, the Inquisition and Anglo carpetbaggers, suffered fatalities that reached 40% in some places. The flu is new.