Swine-Origin Influenza A (H1N1) Viral Infection in Children: Initial Chest Radiographic Findings
- 1 March 2010
- journal article
- Published by Radiological Society of North America (RSNA) in Radiology
- Vol. 254 (3), 934-941
- https://doi.org/10.1148/radiol.09092083
Abstract
Purpose To evaluate initial chest radiographic findings of swine-origin influenza A (S-OIV) (also known as H1N1) viral infection in children. Materials and Methods This was an institutional review board–approved, HIPAA-compliant retrospective study of 108 patients who had microbiologically confirmed S-OIV infection and available initial chest radiographs obtained between April 2009 and October 2009. The final study group was divided on the basis of clinical course (group 1, outpatients without hospitalization [n = 72]; group 2, inpatients with brief hospitalization [n = 22]; group 3, inpatients with intensive care unit admission [n = 14]). Two pediatric radiologists blinded to patient group and lung parenchymal, airway, pleural, hilar, and mediastinal abnormalities systematically reviewed initial chest radiographs. Lung parenchyma and airways were evaluated for pattern (peribronchial markings, consolidation, and ground-glass, nodular, and reticular opacity), distribution, and extent of abnormalities. Radiographs were assessed for presence of pleural effusions or lymphadenopathy. Medical records were reviewed for underlying medical conditions and patient outcomes. Association between frequency of underlying medical conditions and clinical course of S-OIV infection among study groups was evaluated with the Pearson χ2 test. Results The frequency of normal chest radiographs was significantly higher in group 1 (n = 48) than in groups 2 (n = 1) and 3 (n = 0) (P < .001, Pearson χ2 test). Among patients with abnormal radiographs, the most common finding in group 1 was prominent peribronchial markings with hyperinflation (n = 17), whereas the most common findings in groups 2 (n = 12) and 3 (n = 12) were bilateral, symmetric, and multifocal areas of consolidation, often associated with ground-glass opacities. Nodular opacities, reticular opacities, pleural effusion, or lymphadenopathy were not observed in any patient. An increased frequency of underlying medical conditions was observed in patients with greater severity of illness due to S-OIV infection (group 3, 71%; group 2, 59%; group 1, 31%) (P = .003, Pearson χ2 test). All 84 patients with available follow-up information have fully recuperated from S-OIV infection. Conclusion Initial chest radiographs in children with a mild and self-limited clinical course of S-OIV infection are often normal, but they may demonstrate prominent peribronchial markings with hyperinflation. Bilateral, symmetric, and multifocal areas of consolidation, often associated with ground-glass opacities, are the predominant radiographic findings in pediatric patients with a more severe clinical course of S-OIV infection. © RSNA, 2009Keywords
This publication has 9 references indexed in Scilit:
- Imaging Findings in a Fatal Case of Pandemic Swine-Origin Influenza A (H1N1)American Journal of Roentgenology, 2009
- Conventional Wisdom: Unconventional VirusAmerican Journal of Roentgenology, 2009
- Swine-Origin Influenza A (H1N1) Viral Infection: Radiographic and CT FindingsAmerican Journal of Roentgenology, 2009
- Chest Radiographic and CT Findings in Novel Swine-Origin Influenza A (H1N1) Virus (S-OIV) InfectionAmerican Journal of Roentgenology, 2009
- Pneumonia and Respiratory Failure from Swine-Origin Influenza A (H1N1) in MexicoNew England Journal of Medicine, 2009
- Fleischner Society: Glossary of Terms for Thoracic ImagingRadiology, 2008
- Interpretation of Chest Radiographs in Infants with Cough and FeverRadiology, 2005
- Measurement Variability and Confidence Intervals in Medicine: Why Should Radiologists Care?Radiology, 2003
- Two-sided confidence intervals for the single proportion: comparison of seven methodsStatistics in Medicine, 1998