Finally, in an effort to identify cytokine, chemokine, and growth factor plasmatic levels associated with severity, statistical analyses were performed after stratification of the CHIKF patients according to severity. It was observed that an increase in levels of IL-1b and IL-6, and a decrease in RANTES respectively were associated with disease severity (Figure 3a) . The levels of all other markers were not significantly different ( Figure S2 and S3).