Trench fever is an infectious disease caused by the bacterium Bartonella quintana. It was first identified during World War I, where it affected soldiers living in unsanitary conditions in the trenches. The disease is transmitted through body lice and is characterized by symptoms such as high fever, severe headaches, and muscle pain. The illness typically lasts for about a week and can recur multiple times. While trench fever is not usually life-threatening, it can lead to complications if left untreated. Treatment often involves antibiotics, which can effectively eliminate the infection and alleviate symptoms.