Figure 3 shows the difference in the proportion of recent and long-standing infections between MSM and heterosexuals, by year of diagnosis. At multivariate analysis, the proportion of recent infections was significantly higher among males, people aged 15–44 years, Italians, individuals diagnosed in Northern and Central Italy, heterosexual males, MSM, and people with CD4 count at diagnosis ≥ 350 cells/uL (Table 2). This evidence concerns the gene CD4 and infection.