In HIV-infected individuals, latent TB treatment commonly uses INH for 9 months or 3HP (weekly INH + rifapentine for 12 weeks) depending on ART interactions and guidelines.

• A. Rifampin daily for 4 months
• B. Ethambutol for 9 months
• C. Isoniazid for 9 months or 3HP (weekly INH + rifapentine for 12 weeks) depending on ART interactions and guidelines
• D. Pyrazinamide for 6 months

Answer: (C)

Latent TB treatment in people with HIV hinges on regimens that are effective while avoiding problematic interactions with antiretroviral therapy. Isoniazid for nine months remains a solid, well-tolerated option that generally has minimal ART interactions. An alternative that many guidelines support is a shorter course called 3HP—weekly isoniazid plus rifapentine for 12 weeks—which can improve completion rates, but rifapentine and rifamycins can interact with certain ART drugs, so the choice between these options depends on the specific ART regimen and current guidelines. This is why the best answer emphasizes INH for nine months or 3HP, chosen based on ART interactions and guideline recommendations.