Clinical presentation and lung function of children hospitalized with 2009 pandemic influenza a (H1N1) Pneumonia

Abstract

To determine the clinical presentation and subsequent lung function following pneumonia caused by 2009 pandemic influenza A (H1N1), pH1N1, in children aged 5-15 years hospitalized from June to September 2009, we contacted patients meeting the criterion 3-6 months post-hospitalization. Of the 88 patients contacted, 31 (35.2%) had pH1N1 and 57 (64.8%) had infections due to other viral pathogens (non-pH1N1), the mean age was 10.4 years and 52 (59%) were boys. Compared to non-pH1N1 patients, the pH1N1 patients were more likely to have a high fever (96.8% vs 77.2%, p = 0.03), sore throat (58.1% vs 33.3%, p = 0.03), and injected pharynx (80.6% vs 40.4%, p = 0.001). At 3-6 months after pneumonia onset, means for FVC, FEV1, FEV1/FVC, FEF 25-75%, and PEF were within normal limit in both the pH1N1 and non-pH1N1 groups. Five (28%) of 18 pH1N1 children and 4 (20%) of 20 non-pH1N1 children had abnormal lung function results. All were restrictive type. In conclusion, pH1N1 pneumonia were more likely to present with high fever, sore throat, and pharyngeal injection than pneumonia from other viruses. About one quarter of the children who had pH1N1 had restrictive lung function 3-6 months after infection. This number did not differ from the non-pH1N1 group.