RÉSUMÉ
Acute respiratory infection [ARI] is the major cause of morbidity and mortality in children worldwide. Human respiratory syncytial virus [HRSV] is main viral agent of ARI in infants and young children in terms of effect and prevalence. The aim of this study was to investigate HRSV genotypes during one season in Iran. In this cross-sectional study, 107 throat swabs were collected from children less than 5 years of age with acute respiratory infection from October to December 2009. The respiratory samples were obtained from several provinces: Tehran, Isfahan, Hamadan, Zanjan, Kordestan, Lorestan and West Azarbayjan, and were tested for G protein gene of HRSV by RT-PCR. Of the 107 respiratory samples, 24 [22.42%] were positive for HRSV, of which 16 [66.6%] belonged to subgroup A and 8 [33.4%] to subgroup B. Phylogenetic analysis revealed that subgroup A strains fell in two genotypes GA1 and GA2, whereas subgroup B strains clustered in genotype BA. This study revealed that multiple genotypes of HRSV cocirculated during the season 2009 in Iran. Also subgroup A strains were more prevalent than subgroup B strains, and genotype GA1 was predominant during the season