The cryptococcal disease screening and treatment intervention, whereby HIV infected individuals with a CD4+ T-lymphocyte count below 100 cells/μl are reflexively screened for CrAg in blood and if positive, receive pre-emptive antifungal treatment to prevent the development of cryptococcal meningitis, commenced in Gauteng in September 2012 [15]. This evidence concerns the gene CD4 and Cryptococcal meningitis.