II. Pathophysiology

  1. Gram Negative Rod, pleomorphic
  2. Unlike Rickettsia
    1. Not obligate intracellular organism (but is facultative intracellular)
    2. Not anaerobic (Bartonella is obligate aerobe)

III. Associated Conditions

  1. Cat Scratch Disease (Bartonella Henselae)
    1. Cats (>50% infected) transmit the infection via biting or clawing humans
    2. Cats acquire via fleas
    3. Self limited infection in immunocompetent hosts, for whom antibiotics are limited to moderate cases
  2. Bacillary Angiomatosis (Bartonella Henselae, Bartonella Quintana)
    1. Occurs in AIDS (CD4 Count <100 cells/mm3) and other Immunocompromised patients
    2. Vascular skin lesions similar to Kaposi's Sarcoma
    3. Dissemination to bone, CNS, mucous membranes as well as endocarditis and liver (Bacillary Peliosis)
  3. Bacterial Endocarditis (Bartonella Henselae, Bartonella Quintana)
    1. Common cause of culture negative endocarditis (esp. in homeless, see Trench Fever below)
  4. Trench Fever (Bartonella Quintana, previously known as Rickettsia Quintana or Rochalimaea quintana)
    1. Affected millions in World War I
    2. Similar to Epidemic Typhus (Rickettsia prowazekii), as spread via Body Lice
    3. Seen in homeless or Alcoholic patients with Body Lice (which transmit infection)
    4. Presents with Relapsing Fever (every 5 days), Headaches, back and Leg Pain, Splenomegaly and variably, rash
    5. Complicated by bacteremia, Bacillary Angiomatosis or endocarditis
  5. Oroya Fever (Bartonella Bacilliformis)
    1. Infection endemic to Andes of Peru and Ecuador, transmitted by the sandfly
    2. Acute phase with Lymphadenopathy and severe Hemolytic Anemia
    3. Chronic phase (Peruvian Wart, Verruga Peruana) with red-purple Nodules in skin and mucous membranes

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