Genetic mutations in cell surface receptors can alter viral entry into target cells [88], and markers associated with altered susceptibility to infection and disease outcome with CHIKV and other Old World alphaviruses include HLA, TLR-3, TLR-7, TLR-8, MXRA8, and CD209 (DC-SIGN) [3,9,35,88,102]. Here, CD209 is linked to infection.