An unusual rickettsial organism that can multiply within the gut of the body louse and then can be transmitted to humans.Transmission to people can occur by rubbing infected louse feces into abraded (scuffed) skin or into the conjunctivae. It isthe cause of trench fever, a disease that was first recognized in the trenches of World War I, when it is estimated to haveaffected more than a million people in Russia and on the fronts in Europe. Trench fever was again a major problem in themilitary in World War II and is seen endemically in Mexico, Africa, E. Europe, and elsewhere. Urban trench fever occursamong the homeless people and people with alcoholism today. Outbreaks have been documented, for example, in SeattleBaltimore (among injection-drug users), Marseilles (France) and Burundi.

The fever of trench fever is classically a 5-day fever ("quintan fever"). The onset of symptoms is sudden with high fever,severe headache, back pain and leg pain and a fleeting rash. Recovery takes a month or more. Relapses are common.Bartonella quintana also has been found responsible for a disease called bacillary angiomatosis in people infected with Hlvand for infection of the heart and great vessels (endocarditis) with bloodstream infection (bacteremia). The full spectrum ofdisease caused by B. quintana is still unfolding. Syn: Rochalimaea quintana.