Distribution and clinical impact of human respiratory syncytial virus genotypes in hospitalized children over 2 winter seasons

Sequencing studies of the glycoprotein G gene were performed in human respiratory syncytial virus (hRSV) strains detected by reverse-transcription polymerase chain reaction directly from nasopharyngeal aspirates of hospitalized children <= 3 years old over 2 winters. Clinical data were compared between 106 children infected with group A hRSV (96 GA2 genotypes) and 94 children infected with hRSV group B (62 GB3 genotypes). A severity index was defined by assigning 1 point each for the use of > 30% supplemental oxygen, admission to an intensive-care unit, and duration of hospital stay of 15 days. Group A and genotype GA2 strains were associated with greater severity of hRSV disease than were group B strains.