SEROLOGICAL RESPONSE TO RESPIRATORY SYNCYTIAL VIRUS-INFECTION IN PEDIATRIC-PATIENTS WITH A COMPARISON TO IMMUNOFLUORESCENCE AND VIRUS ISOLATION

The serological response to respiratory syncytial virus (RSV) in 125 p ediatric patients hospitalized with acute lower respiratory infection was investigated by enzyme linked immunosorbent assay (ELISA) for spec ific immunoglobulin (Ig) A, IgG, and IgM and complement fixation (CF) test, By ELISA, a 4-fold rise in IgG titre in paired sera was most com monly found, followed by a rise in IgA and IgM titres. Investigation b y ELISA and CF leads to the suggestion that major CF activity against RSV antigens resides in the IgG and not the IgA and IgM classes, No ca se with CF activity failed to be dignosed by ELISA. The youngest infan t who could develop seroconversion was one month old, nevertheless two children older than two years could not. When the three diagnostic me thods were compared, ELISA serology was the most sensitive followed by indirect immunofluorescence (IIF) for antigen detection and virus iso lation, respectively, ELISA could diagnose RSV infection in 45% of the study cases, whereas IIF and virus isolation only diagnosed 26% and 1 4%, respectively. Half of the cases was diagnosed by all of the three methods together.