Chikungunya Virus Strains, Reunion Island Outbreak
Figure. Phylogenetic tree of chikungunya virus (CHIKV) based on partial nucleotide sequences (3´ extremity of E1/3´ untranslated, position 10238–11367). Phylogram was constructed with MEGA 2 (http://megasoftware.net/mega2.html), and the tree was drawn with the Jukes-Cantor algorithm for genetic distance determination and the neighbor-joining method. The percentage of successful bootstrap replicates (1,000 bootstrap replications, confidence probability >90%) is indicated at nodes. The length of branches is proportional to the number of nucleotide changes (percentage of divergence). Asterisks (*) indicate strains isolated in this study. The dark triangle corresponds to viruses of the Democratic Republic of Congo clustering together (GenBank accession nos. AY549575–AY549583). O'nyong-nyong virus (ONNV) sequence has been introduced for correct rooting of the tree.