CD4 and AIDS: In univariate analysis, prior AIDS-related events were associated with a lower probability of new HPV infections (hazard ratio, HR 0.40, 95% CI 0.17–0.95, p = 0.037), while a CD4 count > 500 cells/mm3 was associated with a higher probability (HR 1.89, 95% CI 1.03–3.47, p = 0.041).