CD38 and infection: When compared to pre-infection, significant increases in cellular markers of immune activation were also identified in CD4 (Ki67 + , p = 0.0156 and CD38 + HLA-DR + , p = 0.0156, Fig. 4A, B) and CD8 (Ki67 + , p = 0.0234, Fig. 4C) T cells in the peripheral blood and in CD8 (CD38 + HLA-DR + , p = 0.0078) T cells in the CSF (Fig. 4D), when data from animals in the Early (n = 4, day 8 PI) and Late (n = 4, day 4 PI) groups were combined.