Histopathological examination of infected animals did not reveal any liver or lung damage 3 days post-infection (data not shown) but revealed significantly more hepatic cellular changes including periportal inflammation, necrosis and bridging necrosis in IL-10−/− mice than in WT mice on days 7 and 14 post-infection (Figure 9A) and this was significantly more severe in PyL-infected than PyNL-infected animals on day 7 post-infection. Here, IL10 is linked to infection.