What are the symptoms and treatment options for bartonellosis?

Symptoms and Treatment of Bartonellosis

Bartonellosis presents with a wide range of clinical manifestations from cutaneous lesions to systemic disease, with bacillary angiomatosis and fever being the most common presentations in immunocompromised patients, particularly those with HIV infection and CD4+ counts below 100 cells/μL. 1

Clinical Manifestations

Cutaneous Manifestations

• Bacillary angiomatosis (BA): Most readily identified manifestation
  • Vascular proliferative lesions that can be clinically indistinguishable from Kaposi's sarcoma
  • Can affect nearly every organ system
  • Caused by either B. quintana or B. henselae 1
• Subcutaneous nodules
• Maculopapular rash (in trench fever)
• Papules or nodules (in cat scratch disease)
• Other skin manifestations may include:
  • Purpura
  • Urticaria
  • Erythema nodosum
  • Erythema multiforme
  • Vasculitic lesions 2

Systemic Symptoms

• Fever (often unexplained in late-stage AIDS patients)
• Night sweats
• Weight loss
• Bacteremia (often intermittent and chronic in HIV patients) 1

Organ-Specific Manifestations

• Bacillary peliosis hepatis (only caused by B. henselae)
• Osteomyelitis (usually caused by B. quintana)
• Endocarditis with valvular vegetations (culture-negative)
• Ocular manifestations including retinal artery occlusion
• Renal involvement including membranoproliferative glomerulonephritis 3

Diagnosis

1. Histopathologic examination of biopsied tissue:

   • BA lesions show vascular proliferation
   • Modified silver stain (Warthin-Starry) demonstrates numerous bacilli
   • Tissue Gram staining and acid-fast staining are negative 1

2. Serologic testing:

   • Available at CDC, some state health labs, and private laboratories
   • Limited utility in advanced HIV infection (up to 25% of culture-positive patients may never develop antibodies)
   • In immunocompetent patients, antibodies may not be detectable for 6 weeks after infection 1

3. Blood culture:

   • Using EDTA tubes
   • Difficult to isolate due to fastidious nature of Bartonella
   • Prolonged incubation may be required 1

4. PCR methods:

   • Available for identification and speciation of Bartonella
   • Limited availability 1

Treatment

First-Line Treatment

• Erythromycin or doxycycline are considered first-line treatments for bartonellosis based on reported experience in case series 1
• Therapy should be administered for >3 months 1
• For CNS involvement or severe infections, doxycycline with or without rifampin is the treatment of choice 1

Alternative Treatments

• Clarithromycin or azithromycin have been associated with clinical response
• Azithromycin is recommended for patients less likely to comply with more frequent dosing schedules 1

Treatments to Avoid

• Penicillins and first-generation cephalosporins have no in vivo activity and should not be used 1
• Quinolones and TMP-SMX have variable in vitro activity and inconsistent clinical response 1

Special Considerations

• For patients with Bartonella CNS or ophthalmic lesions, treatment with doxycycline and rifampin for 2-4 weeks before initiating antiretroviral therapy is recommended 1
• Patients treated with oral doxycycline should be cautioned about pill-associated ulcerative esophagitis 1

Prevention

Risk Reduction

• For B. henselae prevention:

  • Consider risks of cat ownership for immunocompromised persons
  • If acquiring a cat, choose one >1 year old in good health with documented health history
  • Avoid stray cats and cats with flea infestation
  • Avoid rough play with cats and situations where scratches are likely
  • Promptly wash any cat-associated wounds
  • Implement comprehensive flea-control program for cats 1

• For B. quintana prevention:

  • Avoid and treat body lice infestation
  • Homeless or marginally housed persons should be informed about risks associated with body lice 1

Chemoprophylaxis

• Primary chemoprophylaxis for Bartonella-associated disease is not recommended
• Note that MAC prophylaxis using a macrolide or rifamycin has been shown to be protective against developing Bartonella infection in a retrospective case-control study 1

Clinical Pitfalls and Caveats

1. Diagnostic challenges:

   • Bartonellosis can mimic other conditions (especially Kaposi's sarcoma in HIV patients)
   • Blood cultures are often negative despite active infection
   • Serologic testing may be negative in up to 25% of culture-positive patients with advanced HIV 1

2. Treatment considerations:

   • Clinical relapse is common despite various prescribed regimens 4
   • Only aminoglycosides display in vitro bactericidal activity against intracellular Bartonella species 4
   • Long-term therapy (>3 months) is often required for complete resolution 1

3. Monitoring:

   • Patients should be monitored for recurrence after treatment
   • In those who develop anti-Bartonella antibodies, monitoring antibody levels may correlate with resolution or recrudescence of infection 1