What is the recommended treatment for Brucella osteomyelitis?

Treatment of Brucella Osteomyelitis

The recommended treatment for Brucella osteomyelitis is doxycycline 100 mg twice daily for 3-6 months plus rifampicin, with the addition of streptomycin 15 mg/kg daily intramuscularly for the first 2-3 weeks. 1

First-Line Treatment Regimen

The treatment of Brucella osteomyelitis requires a combination antibiotic approach:

1. First-line regimen (DOX-STR):

   • Doxycycline: 100 mg twice daily orally for 3-6 months
   • Streptomycin: 15 mg/kg daily intramuscularly for 2-3 weeks

2. Alternative regimen:

   • Doxycycline: 100 mg twice daily orally for 3-6 months
   • Rifampicin: 600-900 mg daily orally for 3-6 months

Treatment Duration

• Uncomplicated Brucella osteomyelitis: Minimum 3 months of antibiotic therapy 1
• Complicated spinal brucellosis (with abscesses): 6 months or longer 1

The Infectious Diseases Society of America (IDSA) notes that in a review of 96 patients with brucellar vertebral osteomyelitis, 65.6% were successfully treated with antimicrobial therapy alone, with the two most common regimens being:

1. Streptomycin (2-3 weeks) + doxycycline (3 months)
2. Doxycycline + rifampin (both for 3 months) 2

Evidence for Treatment Selection

Evidence supports doxycycline-streptomycin (DS) over doxycycline-rifampin (DR) for Brucella osteomyelitis:

• Multiple studies show that DS regimen is more effective than DR regimen, with lower relapse rates 3
• For patients with spondylitis specifically, DS appears to be significantly more effective than DR 4
• Treatment failure rates of approximately 20% have been reported in patients with brucellar vertebral osteomyelitis regardless of regimen 2

Indications for Surgical Intervention

Surgical intervention should be considered in the following scenarios:

1. Progressive neurologic deficits
2. Progressive spinal deformity
3. Spinal instability with or without pain despite adequate antimicrobial therapy
4. Persistent or recurrent bloodstream infection without alternative source
5. Worsening pain despite appropriate medical therapy
6. Presence of abscesses requiring drainage 2, 1

The spine (especially with cervical involvement) should be immobilized to prevent neurological complications 1.

Special Considerations

• Monitoring: Regular clinical assessment, inflammatory markers (CRP), and imaging are essential to evaluate treatment response
• Treatment failure: Consider surgical intervention if there is no improvement after appropriate antibiotic therapy
• Imaging: MRI of the spine is mandatory when spinal involvement is suspected 1

Common Pitfalls and Caveats

1. Inadequate treatment duration: Shorter courses (<3 months) lead to higher relapse rates (22% vs. 4.8%) 5
2. Monotherapy: Should be avoided as it results in higher relapse rates (13% vs. 4.8%) compared to combination therapy 5
3. Delayed diagnosis: Consider brucellosis in patients with new or worsening back pain and fever, especially in endemic regions 1
4. Inadequate follow-up: Patients should be monitored for at least 12 months after treatment completion to detect relapses
5. Surgical timing: Surgery should not be performed solely based on worsening imaging findings at 4-6 weeks if clinical symptoms, physical examination, and inflammatory markers are improving 2

Brucella osteomyelitis requires prolonged antibiotic treatment and careful monitoring to prevent complications and ensure complete eradication of the infection.