As baseline opportunistic infections, lower CD4 count, stage 4 HIV, and delayed ART initiation are associated with poorer retention, CD4 recovery, and morbidity and mortality, our findings suggest that index testing services may be beneficial in bringing PLH into treatment at an earlier stage of HIV disease, decreasing delays between HIV testing and ART initiation, and, ultimately, improving patient outcomes. The gene discussed is CD4; the disease is Opportunistic infection.