Pruned quasi-median network of CHIKV partial E1 gene sequences. 428 nucleotides of E1 gene (n = 108) was used to generate the network, here a specific color code are assigned to each state/Nation and diameter of nodes corresponds to the sample size within each node. The edges joining the nodes are not in scale. Hypothetical ancestral strains or strains not sampled are also represented as small nodes white in color. The proposed evolutionary path is shown by red arrows. Sky blue star represents substitution E1 K211E.