Incidence of viral infection detected by PCR and real-time PCR in childhood community-acquired pneumonia: A meta-analysis

Several studies examining the incidence of viral infection in childhood community-acquired pneumonia (CAP) utilizing polymerase chain reaction (PCR) or real-time PCR methods have been reported. We systematically searched Pubmed and Embase for studies reporting the incidence of respiratory viral infection in childhood CAP. The pooled incidences of viral infection were calculated with a random-effects model. Sources of heterogeneity were explored by subgroup analysis and a univariant metaregression analysis. We included 21 eligible reports in our study. We found significant heterogeneity on the incidence of viral infection in childhood CAP. The random effects pooled incidence was 57.4% (95% confidence interval (CI): 50.8-64.1). The pooled incidence of mixed infection was 29.3% (95%CI: 23.0-35.6) with considerable heterogeneity. The pooled incidence of mixed infection was 29.3% (95%CI: 23.0-35.6). Rhinovirus, respiratory syncytial virus (RSV) and bocavirus were found to be the three most common viruses in childhood CAP. We also demonstrated that respiratory viruses were detected in 76.1% of patients aged 1 year, 63.1% of patients aged 2-5 years and 27.9% of patients aged6 years. We conclude that respiratory viruses are widely detected in paediatric patients with CAP by PCR or real-time PCR methods. More than half of viral infections are probably concurrent with bacterial infections. Rhinovirus, RSV and bocavirus are the three most frequent viruses identified in childhood CAP; the incidence of viral infection decreased with age.