Genetic diversity and evolutionary dynamics of respiratory syncytial virus over eleven consecutive years of surveillance in Senegal.

•Phylogenetic analysis showed that there were four genotypes of HRSV-A and two genotypes of HRSV-B, with a predominance of ON1 and BA9.•The evolutionary rate of genotype ON1 was similar to that of the BA9 genotype (5.16 × 10−3 subs/site/yr).•The rapid increase of effective population size in early 2013 was coincided with the first appearance of the ON1.•The amino acid substitutions under positive selection pressure P274L in HRSV-A and P219L in HRSV-B were found significant by all four selection models.