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An In vitro Model to Study Immune Responses of Human Peripheral Blood Mononuclear Cells to Human Respiratory Syncytial Virus Infection
Published on: December 10, 2013
Respiratory syncytial virus load predicts disease severity in previously healthy infants
John P DeVincenzo1, Chadi M El Saleeby, Andrew J Bush
1Department of Pediatrics, University of Tennessee School of Medicine, Memphis, Tennessee, USA. jdevincenzo@utmem.edu
Insights
Higher respiratory syncytial virus (RSV) loads in infants correlate with increased disease severity and longer hospital stays. This finding is crucial for understanding RSV pathogenesis and antiviral effectiveness.
Area of Science:
- Pediatric infectious diseases
- Virology
- Clinical epidemiology
Background:
- Understanding the relationship between viral load and respiratory syncytial virus (RSV) disease severity is crucial for pathogenesis insights.
- Predicting the efficacy of antiviral treatments for RSV infections relies on this understanding.
Purpose of the Study:
- To investigate the association between viral load and clinical severity in infants hospitalized with RSV.
- To identify predictors of severe RSV disease in previously healthy infants.
Main Methods:
- Prospective study of 141 previously healthy infants (<24 months) with natural RSV infection.
- Quantitative viral load measurement from nasal washes shortly after hospitalization.
- Analysis of clinical data including hospitalization duration, congenital anomalies, weight, respiratory failure, and intensive care unit (ICU) admission.
Main Results:
- RSV load decreased with longer symptom duration before collection.
- Male infants exhibited higher RSV loads than females.
- Higher nasal RSV load independently predicted longer hospitalization (0.8 days per log increase), respiratory failure, and ICU admission.
- Lower weight and congenital anomalies were also significant predictors of severity.
Conclusions:
- Elevated RSV loads in previously healthy infants predict increased disease severity.
- Nasal viral load is a valuable biomarker for predicting clinical outcomes in RSV infections.
- Findings support the potential role of viral load in guiding antiviral therapy decisions.
Background:
Elucidating the relationship between viral load and respiratory syncytial virus (RSV) disease severity is critical to understanding pathogenesis and predicting the utility of antivirals.
Methods:
Previously healthy, naturally RSV-infected infants <24 months old not treated with ribavirin, passive antibody, or corticosteroids were prospectively studied (n=141). Viral loads were measured by fresh quantitative culture from nasal washes collected at a single time point shortly after hospitalization.
Results:
The subjects' mean age was 112.1 days, and the mean estimated gestational age at birth was 38.38 weeks. RSV load decreased with longer durations of symptoms before specimen collection (P=.01). Male subjects had higher RSV loads than female subjects (P=.036). Significant independent predictors of longer hospitalization were congenital anomaly (P<.0001), lower weight on admission (P=.028), and higher nasal RSV load (P=.008). A 1-log higher RSV load predicted a 0.8-day longer hospitalization. Lower weight and higher RSV load were also independently associated with respiratory failure (P<.0005 and P=.0049, respectively) and requirement for intensive care (P=.0007 and P=.0048, respectively).
Conclusions:
In previously healthy infants, higher RSV loads measured at capturable time points after symptom onset predict clinically relevant measures of increased disease severity.
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