Bartonella sp. are gram-negative rods, which were previously classified as rickettsiae. They are facultative intracellular organisms that generally live in red blood cells and endothelial cells. They cause several rare diseases: Cat scratch disease An acute febrile anemia (Oroya fever) Chronic cutaneous eruption (bacillary angiomatosis) Disseminated disease (trench fever) The risk is in immunocompromised hosts higher (see table: infections caused by Bartonella). The Bartonella infection (bartonellosis) is acquired by people usually via an insect vector. Infections caused by Bartonella species manifestations * Endangered insect vectors therapy bacillary angiomatosis B. henselae, B. quintana, warty, fleshy skin lesions Disseminated visceral disease lymphadenopathy hepatosplenomegaly Immunocompromised patients lice, fleas doxycycline , azithromycin, erythromycin Five days fever B. quintana Prolonged or recurrent fever bacteremia endocarditis people live crowded or henselae in lack of hygienic conditions immunodeficient patients at increased risk of disseminated infection body louse doxycycline , erythromycin, rifampin cat scratch disease as lymphadenopathy fever endocarditis in patients who have had a heart valve disease owners of cats immunodeficient P atienten at increased risk of disseminated infection may cat fleas (which also transmit the pathogen among cats) doxycycline , erythromycin, rifampin Oroyafieber, Verruga peruana, Carrion’s disease as bacilliformis Acute febrile hemolytic anemia, skin lesions similar to those secondary in bacterial angiomatosis Infections inhabitants of the Andes at altitudes of 600-2400 m Phlebotomus sandfly doxycycline , chloramphenicol, rifampin, fluoroquinolones, streptomycin * In normal defense In general, doxycycline is preferred. The treatment is usually required in patients with normal immune systems, however, endocarditis can complicate bacteremia by Bartonella.