Viral etiology of acute respiratory tract infections in children presenting to hospital - Role of polymerase chain reaction and demonstration of multiple infections

Background: Viral lower respiratory tract infections are a leading cause of hospitalization for young children. Methods: We used polymerase chain reaction (PCR) and conventional methods of cell culture and antigen detection to establish the viral etiology of acute respiratory tract infections in 75 hospitalized children. Results: One or more viral pathogens were detected in 65 (87%) children, with respiratory syncytial virus being the most commonly identified virus (36 children). Other viruses identified included influenza virus types A and B, parainfluenzavirus type 3, adenovirus, enterovirus, rhinovirus, coronavirus and human metapneumovirus. PCR increased the diagnostic yield significantly compared with antigen detection and culture, with 39 (21%) diagnoses identified by this method. Multiple infections were identified in 20 (27%) children. Conclusions: PCR-based methodologies offer increased sensitivity for the detection of most respiratory viruses in young children. The inclusion of PCR into diagnostic testing strategies is needed to broaden our understanding of the natural ecology of respiratory viruses and the significance of multiple infections.