Etiology and Clinical Features of Acute Viral Lower Respiratory Tract Infection in Apparently Healthy children

Nah, Song Yi; Hong, Jeong Yun; Choi, Eun Hwa; Lee, Hoan Jong

Abstract

PURPOSE
Acute lower respiratory tract infections(LRIs) are an important cause of pediatric morbidity and mortality. Causes of acute LRI in infants and children include bacteria, mycoplasma and respiratory viruses. Understanding of the epidemiology, etiology and clinical features of acute viral LRI is essential to improve the methods of prevention, diagnosis and management of these infections.
METHODS
Viral etiologic agents and clinical features of acute viral LRI were studied from November 1990 through April 1994 in apparently healthy children. Nasal aspirates were collected from 334 children, who visited or admitted to Seoul National University Hospital due to acute LRI. Viral agents were detected by virus isolation and/or antigen detection by indirect immunofluorescent staining. Medical records of children with proven viral LRIs were reviewe retrospectively.
RESULTS
1) One or more viral agents were identified in 162 cases(48.45%). 2) The pathogens identified were RSV(54.6%), adenovirus(12.8%), parainfluenza virus type 3(12.1%), influenza A virus(8.5%), parainfluenza virus type 1(5.7%), influenza B virus(1.4%), parainfluenza type 2(1.4%) and mixed(two) viruses(3.5%). 3) Mean age was 15 months and acute viral LRIs occurred mostly in the first two years of life(82%). 4) Clinical patterns of viral LRI were pneumonia(45%), bronchiolitis(32%), croup(13%) and tracheobronchitis(2.1%). 5) Forty-three percents of febrile patients had fever of 39 degrees C or more and 44.5% had fever for 5 days or more. 6) Leukocytosis and increased CRP(more than 3+) were detected in 23% and 16%, respectively. 7) The major radiologic features are parahilar peribronchial infiltration, overaeration and consolidation.
CONCLUSIONS
We studied the etiologic agents and clinical features of acute viral LRI in apparently healthy children, the results of which may be helpful to the clinicians and further studies are needed for prevention and treatment of acute viral LRI.