Viral lower respiratory tract infections are the leading cause of hospitalizations in preschool children. Clinical pictures of different viral causes are not well characterized. The aim of this study was to establish the differences in clinical and laboratory characteristics between the different viral causes of lower respiratory tract infections in preschool children.
We included 278 preschool children hospitalized because of lower respiratory tract infection. White blood cell count and C-reactive protein values were determined and chest X-ray was performed in most patients. Polymerase chain reaction assay was used for the detection of viral pathogens from nasopharyngeal swab.
Pneumonia was present in 71.4 % of all coronavirus infections, 35.1 % of all respiratory syncytial virus infections, and 13.0 % of all rhinovirus infections. Coronavirus (p = 0.03) and respiratory syncytial virus (p < 0.01) were retrospectively shown to be associated with the presence of pneumonia and rhinovirus (p < 0.01) with the absence of pneumonia. Wheezing was present in 81.5 % of all rhinovirus infections and in only 33.3 % of all adenovirus infections. Rhinovirus (p < 0.01) was associated with the presence of wheezing and adenovirus (p = 0.05) with the absence of wheezing. In adenovirus infections mean C-reactive protein value was 72.4 mg/L and white blood cell count 19.000/µl, both significantly higher than in other viruses (p < 0.01).
Clinical and laboratory characteristics of viral lower respiratory tract infections significantly differ. With the advance of viral detection methods and increase of knowledge it becomes possible to characterize different respiratory viral infections and to improve the differential diagnosis.