An HIV-positive patient (CD4 = 50 cells/µL) is found to have Mycobacterium avium complex (MAC) bacteraemia. Which combination is currently preferred for treatment of disseminated MAC in HIV?

• A Isoniazid + rifampicin + pyrazinamide + ethambutol for 6 months (standard TB regimen)
• B Clarithromycin + ethambutol (+ rifabutin in severe disease) for at least 12 months ✓
• C Azithromycin monotherapy for 6 months followed by lifelong prophylaxis with ciprofloxacin
• D Amikacin + ciprofloxacin for 4 months, which achieves sterilisation of bloodstream

Explanation

Disseminated MAC (DMAC) in advanced HIV is treated with a macrolide (clarithromycin 500 mg BD or azithromycin 500 mg OD) plus ethambutol 15 mg/kg/day as the backbone, with rifabutin added as a third drug in severe or high-burden disease. Rifabutin (not rifampicin) is preferred due to fewer drug–drug interactions with antiretrovirals. Treatment duration is at least 12 months and continued until CD4 >100 cells/µL for >6 months on ART. Standard 4-drug TB therapy is ineffective against MAC. Monotherapy leads to rapid macrolide resistance.

Reference: Ananthanarayan & Paniker's Textbook of Microbiology, 11th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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