There was an increased risk of a stroke in patients with untreated HIV infection (aOR 4.48 [2.44–8.24], p < 0.001), but the highest risk was in the first 6 months after starting antiretroviral therapy (ART) (aOR 15.6 [4.21–46.6], p < 0.001); this group had a lower median CD4+ T-lymphocyte count (92 vs 375 cells/mm3, p = 0.004). This evidence concerns the gene CD4 and HIV infectious disease.