Microbiological and chest X-ray studies on influenza B virus-associated pneumonia.

Introduction: The signs and symptoms of influenza B are commonly ignored. Therefore, very few clinical reports are available. This study is an attempt to evaluate the clinical features and characteristics of influenza B virus-associated pneumonia patients.

Objective: The aim of this study is to investigate the microbiological and characteristics of influenza B virus-associated pneumonia patients.

Methodology: Patients with <16 years old with a clinical diagnosis of influenza B virus infection and who had chest radiography within 2 days were enrolled. A total of 49 patients were categorised as the pneumonia group by clinical symptoms and chest X-ray (CXR) findings, whereas 107 patients were categorised as the non-pneumonia group based on the laboratory data and normal CXR findings.

Results: The study observed that the age of the patients in the pneumonia group was significantly younger than the non-pneumonia group. The white blood cell (WBC) count of the pneumonia group was also higher. However, the haemoglobin (Hgb) level was lower in the pneumonia group. The C-reactive protein (CRP) level of the pneumonia group was also significantly high. The CXR findings revealed that 28.57% of patients had alveolar consolidation, 32.65% had interstitial infiltration and 40.82% had ground glass opacity.

Conclusions: High clinical suspicion is required to detect pneumonia in influenza B virus patients. Based on the CXR findings, the study also suggests that patients with pleural effusion and positive bacterial culture need more attention for the severity of clinical outcome. Moreover, critical care should be given to paediatric patients having higher WBC count, higher CRP level and lower Hgb. These parameters would be helpful to differentiate primary pneumonia from non-pneumonic influenza.