Respiratory syncytial virus infection in children hospitalized for wheezing : Virus-specific studies from infancy to preschool years

To evaluate whether the presence of immunoglobulin G (IgG) antibodies against respiratory syncytial virus (RSV) in early childhood is associated with later asthma, and to evaluate a new diagnostic test for RSV, reverse-transcription polymerase chain reaction (RT-PCR), comparing it to the antigen and antibody assays initially used in RSV diagnostics in the present cohort. At the start of the study in 1992-1993, RSV was studied by antigen detection (using time-resolved fluoroimmunoassay) and complement-fixing antibody assay. Advances in methodology allowed us to supplement RSV studies by RT-PCR in frozen nasopharyngeal aspirates obtained on admission, and by specific IgG antibodies (using enzyme immunoassay) in frozen serum samples obtained during the follow-up. On admission, 29 of the 100 children hospitalized for wheezing at