What is the treatment for Bartonella henselae infections?

Treatment of Bartonella henselae Infections

Erythromycin or doxycycline are the first-line treatments for Bartonella henselae infections, administered for at least 3 months, with doxycycline (with or without rifampin) being the preferred choice for severe infections including CNS involvement. 1

First-Line Treatment Options

For immunocompetent patients with typical cat scratch disease:

• Azithromycin is effective for uncomplicated lymphadenopathy, given as 500 mg on day 1 followed by 250 mg daily for 4 additional days (for patients >45 kg), or 10 mg/kg on day 1 and 5 mg/kg for 4 more days (for patients <45 kg) 2
• Many cases are self-limited and resolve spontaneously within 2-4 months without antibiotic therapy 3, 4
• When antibiotics are used, azithromycin has been shown to speed recovery 5

For HIV-infected or immunocompromised patients with bacillary angiomatosis, peliosis hepatis, or bacteremia:

• Erythromycin and doxycycline are considered first-line treatment based on successful case series experience 1
• Treatment duration must be at least 3 months 1
• Both agents have demonstrated efficacy for treating BA, peliosis hepatis, bacteremia, and osteomyelitis 1

Treatment for Severe or CNS Infections

Doxycycline with or without rifampin is the treatment of choice for:

• Central nervous system involvement 1
• Severe bartonellosis infections 1
• Patients with CNS or ophthalmic lesions should receive doxycycline and rifampin for 2-4 weeks before initiating antiretroviral therapy in HIV-infected patients 1

Pediatric dosing for severe infections:

• Doxycycline: 2-4 mg/kg body weight (maximum 100-200 mg/day) orally or IV once daily or divided into 2 doses 6
• Rifampin: 20 mg/kg body weight (maximum 600 mg/day) in combination with doxycycline or erythromycin 6

Alternative Treatment Options

Macrolide alternatives when first-line agents fail or cannot be tolerated:

• Clarithromycin or azithromycin have been associated with clinical response and can serve as alternatives 1
• Azithromycin is particularly useful for patients unlikely to comply with more frequent dosing schedules required for doxycycline or erythromycin 1
• Erythromycin: 30-50 mg/kg body weight (maximum 2 g/day) is an alternative first-line agent, especially in younger children where doxycycline may not be preferred 6

If azithromycin fails for lymphadenitis:

• Switch to doxycycline with or without rifampin as the recommended next step 6
• Treatment should continue for at least 3 months 6

Antibiotics to Avoid

The following agents should NOT be used:

• Penicillins and first-generation cephalosporins have no in vivo activity against Bartonella 1, 6
• Quinolones and TMP-SMX have variable in vitro activity and inconsistent clinical response in case reports and are not recommended 1, 6

Long-Term Suppressive Therapy

For immunocompromised patients with recurrent disease:

• Long-term suppression with doxycycline or a macrolide is recommended as long as CD4+ count remains <200 cells/µL 1, 6
• Suppressive therapy can be discontinued after 3-4 months of therapy when CD4+ count remains >200 cells/µL for >6 months 1, 6
• Some specialists recommend continuing until Bartonella titers have decreased by fourfold 1

Important Clinical Caveats

Medication administration precautions:

• Patients on oral doxycycline must be cautioned about pill-associated ulcerative esophagitis, which occurs most often when taken with minimal liquid or at bedtime 1, 6
• Always take doxycycline with adequate fluid and avoid lying down immediately after administration 1

Treatment failure considerations:

• If no improvement occurs with initial therapy, consider one or more second-line alternative regimens 1
• For azithromycin failure specifically, switching to doxycycline with or without rifampin is recommended 6
• If no improvement within 1-2 weeks on alternative regimen, pursue further diagnostic evaluation to rule out other causes of lymphadenopathy 6

Prophylaxis note:

• Primary chemoprophylaxis for Bartonella is not recommended 1
• However, MAC prophylaxis using macrolides or rifamycins has shown protective effects against developing Bartonella infection in retrospective studies 1