Genetic diversity of DENV-1 at different levels and at different times of viral evolutionary divergence based on a 1,759 nt fragment including the E-gene.

aSequences in datasets ��Serotype 1��, ��Genotype IV�� and ��FP 2001�C2006�� were also used for phylogenetic reconstructions (Figures 2, 3, S1, S2).bThe pairwise distances were calculated among the nucleotide sequences in each dataset (�� nt).cFive samples collected in February 2001 before the beginning of the 2001 outbreak were excluded from the comparative analysis of DENV-1 evolution during the endemic and epidemic periods (a total of 176 samples collected between March 2001 and December 2006 was analyzed).dResults were significantly different between endemic and epidemic periods (see Methods for details of statistical analysis).