Bartonella species are gram-negative bacteria previously classified as Rickettsiae. They are facultative intracellular organisms that typically live within red blood cells (RBCs) and endothelial cells. They cause several uncommon diseases (see table Some Bartonella Infections):
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Regional lymphadenitis and constitutional symptoms (cat-scratch disease)
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An acute febrile anemia (Oroya fever)
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A chronic skin eruption (verruga peruana)
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A chronic cutaneous eruption (bacillary angiomatosis)
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Disseminated disease (trench fever)
Risk is higher in immunocompromised hosts.
Bartonella infection (bartonellosis) is usually acquired by humans via an insect vector.
Some Bartonella Infections
Species |
Manifestations* |
At Risk |
Insect Vector |
Treatment |
B. henselae, B. quintana |
Verrucous, fleshy skin lesions Disseminated visceral disease Lymphadenopathy Hepatosplenomegaly |
Immunocompromised patients |
Lice, fleas |
Doxycycline†, azithromycin, erythromycin |
B. quintana |
Prolonged or recurrent fever |
People living in conditions of crowding or poor hygiene Immunocompromised patients at risk of disseminated infection |
Body louse |
Doxycycline, erythromycin, rifampin (gentamicin IV added for 2 weeks for endocarditis) |
B. henselae |
Lymphadenopathy Fever Endocarditis in patients who have had a valvular heart disorder Encephalopathy |
Owners of cats Immunocompromised patients at risk of disseminated infection |
Possibly cat fleas (which also transmit the organism among cats) |
Azithromycin, doxycycline, rifampin (gentamicin IV added for 2 weeks for endocarditis)† |
Oroya fever, verruga peruana, Carrión disease |
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B. bacilliformis |
Acute febrile hemolytic anemia, skin lesions similar to those in bacillary angiomatosis Secondary infections |
Residents of the Andes Mountains at elevations of 600–2400 m |
Phlebotomussandfly |
Chloramphenicol, often with doxycycline, or sometimes rifampin, fluoroquinolones, macrolides, or trimethoprim/sulfamethoxazole (TMP/SMX) |
* In normal host. |
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† Treatment is not usually required in patients with a normal immune system. |