Clinical and radiological findings in community-acquired pneumonia: A comparison between viral and bacterial infection

Abstract

Effective treatment for community-acquired pneumonia (CAP) requires administration of appropriate empirical therapy based on etiologic, clinical, and radiological features. However, in Korea, CAP is poorly characterized, and data on viral CAP are particularly sparse. Therefore, improper use of antibiotics is common, and is detrimental the potential for development of bacterial. Thus, we investigated clinical and radiological findings for discrimination of viral CAP from bacterial CAP. Etiologic, clinical, and radiological data from 467 patients with CAP at Chungbuk National University Hospital from October 2010 to September 2011 were analyzed retrospectively. Viruses were identified in 23 cases (11.4%); the influenza virus A was the most common virus detected (N=18, 25.4%), followed by the respiratory syncytial virus A (N=14, 17.9%). Bacteria were identified in 48 cases (23.8%); Streptococcus-pneumonia was the most common (N=24, 25.5%), followed by Staphylococcus aureus (N=20, 21.3%). Depending on hospitalization time, the following significant differences were observed between viral and bacterial CAP: on admission, (1) high fever (≥ 38.5°C), (2) purulent sputum, (3) white blood cell count, (4) Creactive protein levels, (5) and bilateral lung involvement on chest X-ray were higher in bacterial CAP; and at discharge, (1) duration of high fever and (2) radiologic improvement within three days were higher in viral CAP. Regarding seasonal patterns, both viruses and bacteria have been identified with relative frequency in the winter season. This study described the etiological, clinical, and radiological findings of viral and bacterial CAP. Conduct of additional largescale, prospective investigations will be required in order to improve the appropriate treatment of CAP.