A 40-year-old cattle farmer presents with undulant fever, sweating, arthralgia and hepatosplenomegaly. Paired serology (acute and convalescent at 3 weeks) for Brucella shows a 4-fold rise in standard agglutination test (SAT) titre (1:80 to 1:320). Blood culture in BACTEC automated system grows a slowly growing, small, Gram-negative coccobacillus after 5 days of extended incubation. What is the treatment of choice for brucellosis?
- A Doxycycline 100 mg twice daily for 6 weeks + rifampicin 600–900 mg daily for 6 weeks ✓
- B Amoxicillin-clavulanate 875/125 mg twice daily for 3 weeks
- C Ciprofloxacin monotherapy for 4 weeks
- D Azithromycin 500 mg daily for 5 days
Explanation
WHO and national brucellosis treatment guidelines recommend combination therapy with doxycycline 100 mg twice daily plus rifampicin 600–900 mg daily, both given for 6 weeks, as the standard first-line regimen for uncomplicated brucellosis. This combination reduces the relapse rate (<5%) compared to monotherapy. Alternatively, doxycycline for 6 weeks + streptomycin 1 g IM daily for 2–3 weeks has higher efficacy but requires parenteral administration. Fluoroquinolone monotherapy has unacceptably high relapse rates. Beta-lactams are not effective as brucellae are intracellular and survive within macrophages.
Reference: Ananthanarayan & Paniker's Textbook of Microbiology, 11th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.