HIV positive individuals with C. cayetanensis co-infection had a significantly higher expression of HLA-DR+CD38+ on CD4+ and CD8+ T lymphocytes as additional markers of immune activation (31.0 [19.2–38.6 IQR] vs. 17.3 [9.5–30.6 IQR], p = 0.002 and 49.3 [42.8–60.9 IQR] vs. 43.4 [27.8–56.7 IQR], p = 0.042, respectively). This evidence concerns the gene CD38 and coinfection.