Clinical characteristics and risk factors of severe bocavirus-positive pneumonia in children and a literature review.

Increasing evidence suggests that human bocavirus (HBoV) is associated with respiratory symptoms in the absence of other identifiable pathogens and may even precipitate severe lower respiratory tract infections. However, only a few studies of severe human bocavirus infections in pediatric patients have been reported. The aim of the current study was to collect and analyze clinical data from children diagnosed with mild pneumonia and severe pneumonia, with an emphasis on those testing positive for HBoV from June 2009 to June 2019. Among the 799 HBoV-positive children included in the study, approximately 5.88% experienced severe pneumonia. Results revealed no significant differences between co-detection and single detection of HBoV-positive pneumonia in the severe and mild groups, supporting the pathogenicity of HBoV. A higher incidence of severe cases was observed in children lacking Bacillus Calmette-Guérin (BCG) vaccination, or with congenital airway or bronchopulmonary dysplasia (P = 0.046, P = 0.017). Overall, these findings indicate that HBoV can be identified in respiratory samples from children with severe pneumonia, denoting its role as a viral pathogen in hospitalized children with this condition. Preterm birth, wheezing history of previous infection, pulmonary underlying diseases such as airway dysplasia or bronchopulmonary dysplasia, and viremia may be the risk factors for severe pneumonia with HBoV positive.