In HIV, prophylaxis against MAC is recommended when CD4 count falls below:

In HIV, prophylaxis against MAC is recommended when CD4 count falls below:

• A. 50 cells per microliter
• B. 200 cells per microliter
• C. 350 cells per microliter
• D. 500 cells per microliter

Answer: (A)

MAC prophylaxis is started when the CD4 count drops very low, because the risk of disseminated Mycobacterium avium complex infection becomes substantial at that level. The standard preventive approach is to begin prophylaxis once CD4 counts fall below about 50 cells per microliter. This targeted threshold helps prevent MAC disease in those who are most vulnerable, especially as they may not yet have robust immune recovery from antiretroviral therapy. Prophylaxis options include azithromycin 1200 mg once weekly or clarithromycin 500 mg twice daily, chosen for effectiveness and tolerability. The plan is to continue prophylaxis until the patient is on effective ART with a sustained CD4 rise (typically above 100 cells/µL for at least 3 months), at which point stopping prophylaxis can be considered. This threshold specifically distinguishes MAC prevention from other opportunistic infection precautions, such as PCP prophylaxis, which is guided by a CD4 count below 200.

MAC prophylaxis is started when the CD4 count drops very low, because the risk of disseminated Mycobacterium avium complex infection becomes substantial at that level. The standard preventive approach is to begin prophylaxis once CD4 counts fall below about 50 cells per microliter. This targeted threshold helps prevent MAC disease in those who are most vulnerable, especially as they may not yet have robust immune recovery from antiretroviral therapy.

Prophylaxis options include azithromycin 1200 mg once weekly or clarithromycin 500 mg twice daily, chosen for effectiveness and tolerability. The plan is to continue prophylaxis until the patient is on effective ART with a sustained CD4 rise (typically above 100 cells/µL for at least 3 months), at which point stopping prophylaxis can be considered. This threshold specifically distinguishes MAC prevention from other opportunistic infection precautions, such as PCP prophylaxis, which is guided by a CD4 count below 200.