The disease plagued humankind for centuries, inflicting deaths by the thousands. Given its frequency among encamped armies, it was often dubbed "camp fever" or "war fever." During the course of Europe's Thirty Years War (1618-1648), typhus, plague and starvation claimed an estimated 10 million people. Occasionally, outbreaks of typhus would even dictate the outcome of entire wars.
When Spanish forces laid siege to the Moorish stronghold of Granada in 1489, an outbreak of typhus reduced the Spanish forces from 25,000 to 8,000 in a single month [source: Conlon]. Due to the ravages of typhus, it would be another century before the Spanish could drive the Moors from Spain. As recently as World War I, the disease caused several million deaths in Russia, Poland and Romania.
Symptoms of epidemic typhus typically include headache, loss of appetite, malaise and a rapid rise in temperature. This quickly develops into a fever, accompanied by chills and nausea. If untreated, the illness affects blood circulation, resulting in spots of gangrene, pneumonia and kidney failure. Progressive heat exhaustion can eventually lead to delirium, coma and cardiac failure.