At what CD4 count should Mycobacterium avium intracellulare prophylaxis be initiated?

Mycobacterium avium complex (MAC) infections are opportunistic infections that commonly affect individuals with advanced HIV infection. The recommendation for initiating prophylaxis against MAC is based on the CD4 count of the patient. Specifically, prophylaxis with azithromycin or clarithromycin should be considered when the CD4 count falls below 50 cells/mm³.

This threshold is set because patients with CD4 counts below this level have a significant risk of developing MAC infections. CD4 counts serve as a critical marker of immune system health in HIV-infected individuals. Below 50 cells/mm³, the risk of opportunistic infections, including MAC, significantly increases, prompting the need for prophylactic treatment to prevent such infections and associated morbidity.

When determining the most appropriate level to initiate prophylaxis, the evidence strongly supports that a CD4 count of less than 50 is the correct cutoff, thereby guiding clinical decisions in managing HIV-infected patients and preventing opportunistic infections.