Etiology and Clinical Features of Viral Lower-respiratory Tract Infections in Children in Winter, 2003

Yun, Byung Ho; Lee, Hee Chul; Chun, Jung Mi; Yoon, So Young; Lee, Woo Gill; Shin, Son Moon

Abstract

PURPOSE
This study was performed to characterize the etiology and clinical features of acute viral lower-respiratory tract infections (LRI). METHODS: Etiologic agents and clinical features of acute viral LRI were studied from October. 2003 through March. 2004 in hospitalized children with LRI (253 cases) at Samsung Cheil Hospital. The viruses were identified by indirect immunofluorescent method. Medical records of patients with proven viral LRI were reviewed retrospectively. RESULTS: Ninety two cases (36.4%) were confirmed as viral infections. The identified pathogens were respiratory syncytial virus (RSV, 76.0%), adenovirus (ADV, 12.0%), influenza virus type A (INFA, 9.8 %), influenza virus type B (INFB, 1.1%) and parainfluenza virus (PIV, 1.1%). Eight four point eight% of patients were younger than 2 years of age. Clinical diagnosis of LRI were pneumonia (56.5%), bronchiolitis (35.9%), tracheobronchitis (4.3%) and croup (3.3%). The clinical symptoms and signs were cough (98.8%), rhinorrhea (82.6%), fever (70.7%), rale (67.4%), wheezing (29.3%), chest retraction (28.3%) and cyanosis (4.3%). The severe respiratory symptoms and signs were more common in RSV-infected patients, even cyanosis could be observed. Seventeen point four percent of patient had fever of 38.5degrees C or higher and their most common etiologic agent was INFA (66.7%). Twenty three point nine percent had fever more than 5 days and common etiologic agent was INFA (77.8%). The elevated WBC count (> 14x10 (3)/microliter) was in 14.1%, and common etiologic agents were INFA (22.2%) and ADV (18.2%). C-reactive protein (CRP > 4.0 mg/dL) was increased in 13.0%, and common in ADV (63.6 %). Increased aspartate aminotransferase (AST)/alanine aminotransferase (ALT) was detected in 10.9%, and the most common etiologic agent was RSV (12.9%). CONCLUSION: The common agents of acute viral LRI were RSV, ADV and INF, respectively. Because the etiologic agents present variable clinical features, it may be helpful to treat and to evaluate acute viral LRI that we should understand their etiologic variability.