The pro-inflammatory cytokines (like IFN-γ) are important in parasite control during early stage infection by activation of TNF-α and nitric oxide (NO) secretion from macrophages, and then a switch to anti-inflammatory cytokines (IL-10, IL-4) with protective immunity crucial for survival of host or parasite during late and chronic stages of trypanosomiasis [13, 14]. This evidence concerns the gene IL10 and infection.