Trypanosome DNA was detected in the brains of animals killed at day 7 post-infection (155.5 ± 88.7) (Fig.3B). By day 14 post-infection the detectable parasite burden had increased significantly (841 ± 192; p = 0.005) compared to the earlier time-point (Fig.3B). The trypanosome load seen in the brains of animals killed at 21 days -post-infection showed a further rise (2332 ± 770). Although this was an increase of approximately 175% the burden was not significantly (p = 0.454) higher than that seen in animals on day 14 post-infection. A further rise in the number of parasites residing in the CNS was observed at day 28 post-infection (6766 ± 1607). The trypanosome load within the brain at this time-point was significantly higher than the levels detected at both 7 days -post-infection (p < 0.001) and14 days -post-infection (p = 0.010) but failed to reach significance when compared to animals killed on day 21 post-infection (p = 0.175). Summary statistics for the trypanosome load measured at each time-point are detailed in Supplementary Table 2.