Detection of respiratory syncytial virus in children with respiratory tract infections by nucleic acid amplification fluorogenic quantitative assay

Objective Nucleic acid amplification (PCR) fluorogenic quantitative assay is used for the diagnosis of respiratory syncytial virus (RSV) infection. This study was designed to explore the sensitivity of PCR fluorogenic quantitative assay for ascertaining respiratory RSV infection and RSV infection conditions by detecting the presence of RSV-RNA related sequences in children.Methods Bronchial and nasopharyngeal secretions specimens from 261 hospitalized children with respiratory tract infections from January 2007 to October 2008 were collected. Respiratory syncytial virus nucleic acid (RNA) in the specimens was measured by PCR fluorogenic quantitative assay. Blood RSV-IgM was detected by enzyme linked immunosorbent assay (ELISA). The sensitivity for ascertaining respiratory RSV infection was compared between the two assays.Results The RSV-RNA positive rate ascertained by PCR fluorogenic quantitative assay (38.7%) was significantly higher than blood RSV-IgM positive rate (21.1%) (P0.01). The RSV-RNA positive rate (43.6%) in children at ages of less than 6 months was significantly higher than that in children at ages of 1 to three years (32.1%) (P0.01). The RSV-RNA positive rate in children with bronchiolitis (58.5%) was the highest,followed by bronchopneumonia (38.2%) and acute bronchitis (20.0%).Conclusions The sensitivity of PCR fluorogenic quantitative assay for ascertaining respiratory RSV infection is higher. RSV is a major pathogen of lower respiratory tract infections in infants and young children. A higher rate of RSV infection is associated with a younger age. RSV infection is the most common in children with bronchiolitis.