Medicine: War and Pestilence

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...