Figure A2. The maximum likelihood phylogenetic tree for chikungunya nonstructural protein 1 (NSP1) sequences (314 bp) constructed using PAUP* under a transitional model with equal base frequencies with a γ-distributed rate of substitution (i.e., TIM+G), as selected by MODELTEST (version 3.7) under the Akaike information criteria. The bracket shows that the PWH patient NSP1 sequence (DQ489788) clusters most closely with the outbreak La Reunion sequence (LR2006_OPY1_Reunion_2006_NSP1, DQ443544). Only bootstrap values >70 are shown and considered significant. The tree is rooted against the earliest sequence (AF490259/Ross_Tanzania_1953).