Clinical significance of pleural effusion in the new influenza A (H1N1) viral pneumonia in children and adolescent

Abstract

Background: Parapneumonic effusion has been reported to develop either in typical bacterial infection or in viral pneumonia with bacterial co-infection and to cause death. Swine-origin influenza A (H1N1) virus infection can be accompanied with pleural effusion; however, there are no reports about the significance of pleural effusion in H1N1 pneumonia. We retrospectively analyzed both the clinical characteristics and the significance of pleural effusion associated with H1N1 pneumonia in children and adolescent.

Method: Eighty-nine patients who were admitted with H1N1 pneumonia were divided into two groups: 17 patients with pleural effusion (i.e., the effusion group), and 72 patients without pleural effusion (the non-effusion group).

Results: Lymphopenia (P = 0.030), elevation of the C-reactive protein (P = 0.026), and positive rate of anti-sptreptolysin O titer (P = 0.040) were significantly increased in the effusion group than in the non-effusion group. In addition, the need for treatment with both oxygen (P < 0.001) and oseltamivir (P = 0.013) was significantly increased in the effusion group. However, there was no significant difference between the two investigated groups in the duration of the treatment with intravenous antibiotics, the time of fever remission calculated from admission, and the days of hospital stay. Also, there was no documented bacterial co-infection in any of the studied groups.

Conclusion: This result suggested that pleural effusion in H1N1 pneumonia could develop without bacterial co-infection and had mild clinical course.