The Illustrious Dead

If you'd like to read more about how Typhus fever destroyed Napoleon's ambition then there's a recent book that makes the case - Stephan Talty's 'The illustrious dead':

When Napoleon invaded Russia in 1812, typhus ravaged his army, killing hundreds of thousands and ensuring his defeat, according to this breathless combination of military and medical history. After summarizing the havoc this disease wreaked on earlier armies and sketching Napoleon's career, the book describes his invasion of Russia with more than 600,000 men. Almost immediately typhus struck. Infected lice excrete the microbe in their feces, and victims acquire the disease by scratching the itchy bite. Talty describes the effects in graphic detail: severe headache, high fever, delirium, generalized pain and a spotty rash. Death may take weeks, and fatalities approached 100% among NapoleonÖs increasingly debilitated, filthy, half-starved soldiers. Talty makes a good case that it was typhus, not General Winter, that crushed Napoleon. Readers should look elsewhere for authoritative histories of NapoleonÖs wars and of infectious diseases, but Talty delivers a breezy, popular account of a gruesome campaign, emphasizing the equally gruesome epidemic that accompanied it.  (Publisher's Weekly review).

I haven't read this one but I think I'll add it to my reading list.

for something a little more immediately accessible you can read Insects,disease, and military history: the Napoleonic campaigns and historical perception. The version online is adapted from a paper of the same name in the American Entomologist. (1995)  41:147-160.