Final answer:
AIDS patients with latent TB usually experience reactivation of TB when their CD4 T-cell count falls below 200 cells/μL, as this indicates significant immunosuppression making them susceptible to opportunistic infections.
Step-by-step explanation:
Patients with HIV/AIDS experiencing latent tuberculosis (TB) are at particular risk for reactivation of the infection as their CD4 T-cell count declines. Reactivation of TB typically occurs when the CD4 T-cell count falls below a critical level, with significant risk increasing as the count drops lower. In the context of HIV infection, reactivation of TB is particularly common when the HIV-infected individual progresses to AIDS and their CD4 count falls below 200 cells/μL. At this stage, the immune system is severely compromised, making the person susceptible to opportunistic infections like TB and others. The latent TB can become active again because the body's immune defenses, which had previously kept it in check, can no longer control the latent infection.