General Information: Bartonella quintana str. Toulouse was isolated from human blood in Toulouse, France in 1993. Causative agent of trench fever. This group of alpha proteobacteria are unique among pathogens in that they cause angiogenic lesions. This organism was first identified as the causative agent of louse-born trench fever during World War I. Up to 800 000 were infected in the trenches because of the louse insect vector that was widespread due to poor sanitation. The disease is now found associated with immunocompromized patients, especially HIV patients and homeless alcoholics.