Clinical Report: Rhinovirus as a Cause of Lower Respiratory Tract Infections in Hospitalized Adults
Overview
This retrospective study of 9544 hospitalized adults identified human rhinovirus (HRV) in 4.6% of cases, with nearly half exhibiting co-infections. Immunofluorescence staining confirmed HRV infection in lower respiratory tract cells, providing histological evidence of alveolar tropism. Male sex, fever, and cough were independent predictors of simple rhinovirus pneumonia.
Background
Human rhinoviruses (HRVs) are well-known causes of upper respiratory infections but their role in adult lower respiratory tract infections (LRTIs) remains debated. HRVs are classified into three species with varying pathogenicity, and while they replicate better at cooler nasal temperatures, recent evidence suggests they can infect bronchial and alveolar cells. Prior studies lacked direct histological confirmation of HRV infection in the lower respiratory tract of immunocompetent adults. This study aimed to clarify HRV's clinical impact, confirm its alveolar tropism, and identify predictors of HRV-associated pneumonia.
Data Highlights
Parameter
Value
Total hospitalized adults screened
9544
HRV-positive patients
437 (4.6%)
Co-infection rate among HRV-positive
49.0% (214/437)
Co-infection types
Bacteria 34.1%, Viruses 25.7%
HRV-positive with pneumonia
224
Simple viral pneumonia cases
34 (7.8%)
IF staining positive for HRV VP3 protein
61.5% (8/13)
Independent predictors of simple rhinovirus pneumonia (OR, 95% CI, P)
HRV was detected in 4.6% of hospitalized adults screened over four years, with seasonal peaks in late winter/early spring and autumn.
Nearly half of HRV-positive patients had co-infections, mostly bacterial or viral, complicating clinical presentation.
Only 7.8% of HRV-positive pneumonia cases met criteria for simple viral pneumonia without other pathogens.
Immunofluorescence staining of lung biopsy specimens confirmed HRV VP3 protein presence in lower respiratory tract cells in 61.5% of tested cases.
Male sex, fever, and cough were independently associated with simple rhinovirus pneumonia, suggesting these as clinical predictors.
Clinical Implications
Clinicians should consider HRV as a potential independent cause of pneumonia in hospitalized adults, especially in males presenting with fever and cough. Despite frequent co-infections, HRV can directly infect lower respiratory tract cells, underscoring the importance of accurate viral diagnostics. Awareness of HRV's role may influence management strategies and infection control measures during seasonal peaks.
Conclusion
This study provides the first histological confirmation that HRV infects lower respiratory tract cells in immunocompetent adults and identifies clinical predictors of HRV-associated pneumonia. These findings support HRV as a significant pathogen in adult lower respiratory infections beyond upper airway involvement.
References
Original Study 2024 -- Lower Respiratory Tract Infections Linked to Rhinovirus in Hospitalized Adults: A Retrospective Analysis
