Bartonella species have been recently recognized as an important human pathogen associated with a wide spectrum of diseases. Four members of the genus are known to cause human infection: Bartonella baciliformis, B. henselae, B. quintana and B. elizabethae. B. baciliformis, the first identified Bartonella species, is the agent of two disease entities, Oroya fever and verruga peruana., B. henselae and B. quintana are two species involved in producing bacteremic syndromes (relapsing fever, trench fever, endocarditis), chronic lymphadenopathy in immunocompetent patients (cat-scrath disease) and chronic vascular lesions in immunocompromised hosts (bacillary angiomatosis and bacillary peliosis hepatis-recognized as new opportunistic infections in HIV-infected patients).