Our findings here, of the higher number of P. knowlesi csp alleles and mtDNA genome haplotypes detected per infection in macaques compared with humans, and the very high prevalence of P. knowlesi in macaques, suggest that presently there is a greater intensity of transmission of P. knowlesi by the vectors among wild macaques, than from macaques to humans. This evidence concerns the gene DNAJC5 and infection.