Clinical characteristics and risk factors of severe pneumonia caused by human bocavirus in children.

BACKGROUND

The aim of this study was to investigate the clinical characteristics of severe pneumonia caused by human bocavirus (HBoV) infection to explore the associated risk factors.

METHODS

We conducted a retrospective review of data from children hospitalized with HBoV pneumonia. Based on the severity of pneumonia, patients were categorized into severe pneumonia and non-severe pneumonia groups. Clinical manifestations, laboratory examination results, chest imaging and pathogens were analyzed. Logistic regression was employed to identify the risk factors for severe HBoV pneumonia.

RESULTS

A total of 334 patients were admitted, with 44 (13.17%) patients diagnosed with severe pneumonia and 290 (86.83%) with non-severe pneumonia. There were no significant differences in age distribution, presence of fever, lung moist rales, pleural effusion and reduced breath sounds between the two groups (all P > 0.05). 57.19% of the HBoV-positive children co-infected with other pathogens and HRV was the most common co-infected pathogens with HBoV. No significant differences were observed in the rate of co-infection between the two groups (χ2 = 0.50, p = 0.48). The univariate analysis revealed significant differences between the severe pneumonia group and the non-severe group in terms of gender distribution, presence of underlying chronic diseases, wheezing, premature delivery, lung wheezing rales, pneumothorax, bronchoscopy procedures, length of hospital stay, duration of symptoms prior to admission, neutrophil count, CRP levels, CKMB levels, IgA levels, CD3+(%), CD3+CD4+(%), CD3+CD8+%, and CD3-CD19+% (all P < 0.05). Multivariate logistic regression analysis identified female gender, wheezing and neutrophil count were independent risk factors and the ratio of CD3+CD4+ cells was protective factor for severe HBoV pneumonia. The cut-off values of neutrophil count and the ratio of CD3+CD4+ cells were 6.81 × 109/L and 32.48 respectively.

CONCLUSION

Our study indicated that female gender, wheezing and neutrophil count greater than 6.81 × 109/L were independent risk factors and the ratio of CD3+CD4+ cells greater than 32.48 was protective factor for severe HBoV pneumonia.