Brucellosis — DTM&H MCQ

Correct answer: E — Doxycycline plus rifampicin for 6 weeks

The correct answer is E, doxycycline plus rifampicin for 6 weeks. This history (unpasteurised goat's milk, occupational exposure, undulant fever, sweats, back pain, Brucella melitensis on culture) is classic for uncomplicated brucellosis without focal complications such as endocarditis or spondylitis-associated abscess. Combination therapy with doxycycline and rifampicin for a minimum of six weeks is the standard first line regimen because monotherapy carries a high relapse rate, and dual tetracycline-based combination therapy reduces relapse compared to single-agent treatment. Rifampicin is added specifically to cover intracellular organisms, since Brucella survives within macrophages and single beta-lactam or short-course agents fail to eradicate it. Why the other options are wrong: C. Albendazole with praziquantel: this combination targets helminths such as neurocysticercosis or hydatid disease, not an intracellular gram-negative coccobacillus like Brucella. B. Azithromycin single dose: a single dose macrolide is used for conditions like uncomplicated chlamydia or some enteric infections, and provides no sustained intracellular activity needed to clear Brucella, guaranteeing relapse. D. Cefalexin for 7 days: a first generation cephalosporin has poor intracellular penetration and Brucella is often only variably susceptible, plus 7 days is far too short for a disease requiring weeks of therapy. A. Metronidazole plus paromomycin: this is the regimen for amoebic liver abscess or invasive amoebiasis, irrelevant to a zoonotic bacterial infection from unpasteurised dairy. Key point: uncomplicated brucellosis needs prolonged combination therapy (doxycycline plus rifampicin for at least 6 weeks) because monotherapy or short courses lead to relapse from persistent intracellular organisms.

Reference: GPnotebook, Brucellosis: Treatment (based on WHO guidance): doxycycline plus rifampicin for 6 weeks as standard regimen, https://gpnotebook.com/pages/infectious-disease/brucellosis/treatment