In a Cox proportional hazards model, subtype D versus B infection and < 100% adherence were the only factors independently associated with an increased rate of virological rebound (Hazard Ratio [HR] = 2.14, 95% CI = 1.12-4.14, p = 0.02; HR = 1.32, 95% CI = 1.09-1.59, p = 0.004) after adjustment for baseline CD4 count and viral load, risk group and ethnicity. This evidence concerns the gene CD4 and infection.