We found that plasma concentrations of sTNFRII (β = 0.361, P<0.001) and either IL-10 levels (β = 0.503, P<0.001) or the ratios IL-10/TNF-α (β = 0.324, P = 0.001) or IL-10/IFNγ (β = 0.476, P<0.001) correlated positively with parasite density in human infection with P. vivax, regardless of the presence of symptoms. This evidence concerns the gene IL10 and infection.