As shown in Table 1, the distribution of genotype revealed significant differences according to gender (χ2 = 25.799, P < 0.001), age (χ2 = 51.906, P < 0.001), education level (χ2 = 22.299, P < 0.001), route of infection (χ2 = 42.681, P < 0.001), CD4 + T lymphocytes counts (χ2 = 19.400, P = 0.038), and TDR (χ2 = 25.686, P < 0.001). The gene discussed is CD4; the disease is infection.