In Europe's bloody wars, for every ten men slain by the enemy, pestilence has killed its thousands. In the Thirty Years' War, an estimated 8,000,000 Germans were wiped out by flea-borne bubonic plague and louse-borne typhus fever. On Napoleon's retreat from Moscow, typhus, dysentery and pneumonia killed 450,000 of the Grand Army's 500,000 men.
World War I was the first war in history in which guns were more deadly than germs. Battlefield deaths totaled 8,000,000; deaths from disease, 3,000,000. Yet, despite the great achievements of medical science, disease was still a potent wartime killer. In 1914, typhus swept through Serbia, spread to...