An additional health care system daily investment of US$1.45, 1.09, 2.13, 4.35, 1.09, and 0.87 would be required for each additional outcome of viral load <50 copies/ml, absence of co-infection, CD4+ >200, 350, and 500 cells/mm3, and optimal immune response, respectively. The gene discussed is CD4; the disease is coinfection.