In conclusion, patients receiving modern ART regimens but who, as a consequence of antiretroviral drug resistance and/or suboptimal medication adherence, had persistent very low CD4+ T cell counts and failed to achieve complete virologic suppression were found to be at high risk of death, particularly from non-AIDS causes, though lower than that reported in patients with comparable CD4+ T cell counts receiving optimal opportunistic infection prophylaxis and antiretroviral therapy in the pre-modern-ART era. Here, CD4 is linked to Opportunistic infection.