Review Question - QID 100822

Patients with CD4 < 50 cells/microliter require antibiotic prophylaxis (typically with azithromycin) against mycobacterium avium-intracellulare (MAI).

Given that HIV is an immune deficiency, HIV positive patients are prone to a variety of opportunistic infections. The specific opportunistic infections that are of concern are dictated by the patient's CD4 count. At CD4 counts < 50 cells/microliter the primary opportunistic infections of concern are M. avium-intracellulare, and CMV reactivation, along with the opportunistic infections possible at higher CD4 counts. Standard prophylaxis against MAI is usually with azithromycin.

Chu and Selwyn review the complications of HIV. They note that opportunistic infections are an important consideration, they have been decreasing in incidence. There are routine screening labs that are necessary in patients with HIV infection, and it is sometimes necessary to switch anti-retroviral medication regimens as part of the management of certain complications (e.g. cardiovascular disease, lipodistrophy)

Currier et al. conducted a randomized trial of discontinuing azithromycin prophylaxis for patients with CD4 counts < 50 with appropriate count increases with appropriate anti-viral therapy. In comparing azithromycin to placebo, they found that the rates of infection with M. avium were not significantly different between the two groups. They also found that patients receiving azithromycin were more likely to discontinue study drug than those receiving placebo.

Illustration A is a table from the CDC of indications for prophylaxis for various opportunistic infections for patients with HIV.

Incorrect answers
Answers 1,3,4 and 5: All of this patients have CD4 counts above 50 cells/microliter and thus do not require prophylaxis against mycobacterium avium-intracellulare. Viral load is not used as an indication for MAI prophylaxis.