The Disease:Trench fever, a louse-transmitted illness, was first identified during World War I in the trenches, which led to its name. It is believed to have affected over a million individuals in Russia and on European battlefields. This disease resurfaced as a significant issue for the military during World War II and continues to be found in regions like Mexico, Africa, Eastern Europe, and beyond.In urban environments, trench fever is prevalent among homeless populations. Documented outbreaks have occurred in places like Seattle, Baltimore (notably among injection drug users), Marseilles (France), and Burundi.The disease is caused by Bartonella quintana (also known as Rochalimaea quintana), an atypical rickettsial organism that proliferates in the body louse's gut. Transmission to humans happens when infected louse feces are rubbed into broken skin or the whites of the eyes.Trench fever typically presents as a five-day fever. Symptoms appear suddenly, including high fever, intense headache, leg pain, and a brief rash. Recovery can take more than a month, with relapses being frequent. In its urban form among the homeless, trench fever can sometimes present with vague or no symptoms at all, as reported in the New England Journal of Medicine (1999).Additionally, the organism B. quintana is linked to bacillary angiomatosis in individuals with compromised immune systems and can cause infections of the heart and major blood vessels.Trench fever is also known by several other names, including Wolhynia fever, quintan fever, five-day fever, Meuse fever, and Werner-His disease. The latter is named after Swiss physician Wilhelm His, Jr. (notable for describing the bundle of His in the heart) and German physician Heinrich Werner (who is different from the Werner associated with Werner's syndrome).