Fig 1. SNP phylogeny of VEEV isolates by parsimony.

Strains are labeled by serotype-country-year collected-strain-host. Country codes are GA = Guatemala, PE = Peru, NI = Nicaragua, VE = Venezuela, CO = Colombia, TR = Trinidad, PA = Panama, US = USA, EC = Ecuador, ME = Mexico, BE = Belize, HO = Honduras, BR = Brazil, AR = Argentina, FG = French Guiana. Host codes are hor = horse, don = donkey, hum = human, mos = mosquito, ham = hamster, mus = mouse. u = unknown. Strains are colored by serotype (blue = IE, green = ID, red = IC, and purple = IAB). Hosts from which the strains were collected are indicated with symbols at the branch tips (red circles = human, orange circles = horses, blue circles = mosquitos, and green squares = hamsters). Counts of the number of alleles shared uniquely by the sequences down each branch are shown at the nodes in blue.