# Etiological characteristics and risk factors for severe disease in bocavirus-associated community-acquired pneumonia in children: a multicenter retrospective study

## TL;DR

This study compares diagnostic methods for bocavirus-related pneumonia in children and identifies risk factors for severe disease.

## Contribution

The study provides new insights into the clinical variability and risk factors for severe bocavirus-associated pneumonia in children.

## Key findings

- tNGS detected more mixed infections than nucleic acid testing in bocavirus-positive pneumonia cases.
- Age under 3 years, plastic bronchitis, and increased prealbumin were identified as independent risk factors for severe disease.
- Clinical profiles of bocavirus-associated pneumonia varied significantly across different centers.

## Abstract

This is a multicenter retrospective study aimed to evaluate the concordance between nucleic acid testing and targeted next-generation sequencing (tNGS) for etiologic detection, and to identify potential risk factors for severe community-acquired pneumonia (SCAP), thereby providing evidence for precision clinical management.

We retrospectively analyzed 191 pediatric Community-Acquired Pneumonia(CAP) cases positive for bocavirus by tNGS from April 2023 to June 2025. Etiologic concordance and coinfection patterns were evaluated. Univariate and multivariate logistic regression identified independent risk factors for SCAP.

191 children were included. Significant heterogeneity was observed among the four centers in age distribution, SCAP incidence, imaging findings, and treatment patterns (P < 0.05). Children’s Hospital, Zhejiang University School of Medicine (ZCH) reported the highest SCAP incidence (50.0%), with markedly higher rates of pulmonary consolidation (66.7%), atelectasis (100.0%), and pleural effusion (16.7%) compared with other centers, whereas DY had the lowest SCAP incidence (11.0%). All cases were bocavirus-positive by tNGS, while the positivity rate by nucleic acid testing was 51.3%. tNGS identified 44 cases of mixed detection (23.0%), including 35 bacterial (18.3%) and 7 viral co-detections (3.7%), whereas nucleic acid testing identified only 9 mixed detections (4.7%). tNGS demonstrated a clear advantage in detecting mixed and bacterial detections (P < 0.001). Multivariate logistic regression revealed that age < 3 years, plastic bronchitis, and increased prealbumin were independent risk factors for SCAP (P < 0.05).

Clinical profiles of bocavirus-associated CAP vary significantly across centers. tNGS offers a broader range of pathogen co-detection compared with conventional nucleic acid testing. Early recognition of high-risk children—particularly those < 3 years with potential plastic bronchitis and viral co-detection—is essential for timely SCAP management.

This multicenter retrospective study was registered with the Chinese Clinical Trial Registry (ChiCTR), a primary registry within the WHO Registry Network. The registration was completed on January 19, 2025 (Registration number: ChiCTR2400080059), with a predefined target of enrolling at least 150 cases.

The online version contains supplementary material available at 10.1186/s12879-026-12543-z.