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Published on: September 22, 2023
Severe Lower Respiratory Tract Infection in Patients With Human Bocavirus Monoinfection in Southeast China
Luona Lin1, Xin Cong1, Wei Li2
1Department of Infectious Diseases, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Children and Adolescents' Health and Diseases, Hangzhou, China.
Insights
Human bocavirus (HBoV) can cause severe lower respiratory tract infections (LRTIs) in children. High viral DNA load and specific genetic variants are linked to critical illness and increased risk.
Area of Science:
- Pediatrics
- Virology
- Infectious Diseases
Background:
- Acute lower respiratory tract infections (LRTIs) pose a significant health burden in children.
- Human bocavirus (HBoV) is an emerging pathogen implicated in pediatric respiratory illnesses.
- Understanding HBoV's role in LRTI severity and identifying risk factors is crucial for clinical management.
Purpose of the Study:
- To investigate the clinical severity of HBoV-associated LRTIs in hospitalized children.
- To identify risk factors contributing to severe and critical disease outcomes caused by HBoV.
- To explore the relationship between viral load, host immune response, and genetic variations in HBoV severity.
Main Methods:
- A prospective cohort study involving children hospitalized with LRTIs.
- Confirmation of HBoV monoinfection using polymerase chain reaction (PCR).
- Analysis of viral DNA load, genome sequences, clinical data, and patient follow-up for one year.
Main Results:
- HBoV monoinfection was confirmed in 65% of HBoV-positive LRTI cases.
- Severe HBoV LRTI occurred in 45.5% of cases, with 10.8% classified as critical.
- Higher HBoV DNA loads (>10^6 copies/mL) and the VP1_L40S variant significantly increased the risk of critical illness.
Conclusions:
- HBoV monoinfection is a significant cause of critical LRTIs in children.
- Elevated HBoV DNA loads, neutrophilia, and the VP1_L40S variant are associated with severe disease.
- These factors may serve as important indicators for predicting HBoV LRTI severity.
Background:
This study aims to investigate the severity and risk factors of acute lower respiratory tract infections (LRTIs) caused by human bocavirus (HBoV) in children.
Methods:
We conducted a prospective cohort study of children hospitalized with LRTIs and confirmed HBoV monoinfection via polymerase chain reaction from March 2022 to February 2024. Viral load and genome analysis were performed, with clinical data collected. Patients were followed for 1 year post-discharge.
Results:
Among 412 hospitalized patients with HBoV-positive LRTIs, 268 (65.0%) had HBoV monoinfection. Severe infection occurred in 45.5%, with 10.8% critical, 6.3% requiring ICU admission, and 2 (0.7%) deaths. Higher HBoV-DNA loads (>10⁶ copies/mL) significantly increased critical disease risk (OR1 = 9.33, 95% CI 2.90-30.09). IFN-γ levels weakly correlated positively with DNA loads (r = 0.20, P = .024) and neutrophil counts (r = 0.26, P = .003). Furthermore, elevated neutrophil counts (>60%) were associated with hypoxemia (P < .001), pulmonary consolidation (P = .034), critical LRTI (P < .001), and ICU admission (P < .001). Despite high HBoV conservation, the VP1_40 (L→S) amino acid variation significantly increased critical LRTI risk (P = .03).
Conclusions:
HBoV monoinfection can cause critical LRTI in children. High DNA load, associated with elevated IFN-γ levels and neutrophilia, along with the viral VP1_L40S variant, may be key factors contributing to severe disease outcomes.
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