Risk factors of severe novel influenza A (H1N1) infections in hospitalized children

Background/Purpose Data on hospitalized novel influenza A (H1N1) infected children are limited and urgently in demand. We conducted a clinical study to identify clinical features and risk factors associated with severe novel H1N1 infections of children in Taiwan. Methods From July 24, 2009 to December 4, 2009, data from 61 hospitalized children infected with 2009 novel H1N1 were collected. Demographics, underlying medical conditions, clinical data, receipt of antiviral therapy, need for intensive care and outcome were analyzed to identify clinical features and risk factors of severe infections. Results Of the 61 inpatients, the male to female ratio was 41 to 20 and the most common age group was between 6 and 12 years (36%). Almost all (98%) patients had fever, 53 (87%) patients received oseltamivir treatment and 51% of them received oseltamivir within 48 hours. Fourteen (23%) needed intensive care and 3 died. Obesity (a Body Mass Index ≥ 25 kg/m 2 in children ≥ 2 years of age, or a body weight ≥ the 95 th percentile in children  3 mg/dL, pleural effusion, and delayed antiviral therapy were significantly associated with the need for intensive care and/or death. Conclusion Obesity, dyspnea, CRP > 3 mg/dL, pleural effusion, and delayed antiviral therapy are significantly associated with severe novel H1N1 infections in children.