Clinical Features, Risk Factors, and Complications Among Pediatric Patients with Pandemic Influenza A (H1N1)

Objective: The authors aimed to describe the epidemiological characteristics, clinical features, risk factors for severe disease, and complications in children with laboratory-confirmed pandemic influenza A (H1N1).

Methods: H1N1 was confirmed by performing reverse-transcriptase polymerase chain reaction (RT-PCR) assay on oropharyngeal swab specimens. The medical charts of a subset of the evaluated patients were reviewed retrospectively; another subset was enrolled prospectively.

Results: A total of 51 patients (44 [86%] > 5 years) were identified to have laboratory-confirmed H1N1. Fever was the most common presenting symptom (92%). Of the 15 hospitalized patients, 4 had asthma, and 5 were overweight or obese. All but 1 of these 9 patients developed influenza-related complications. Overall, 10 of the 15 hospitalized patients (67%) developed an influenza-related complication (6 bronchitis and 4 pneumonia).

Conclusion: In this cohort, most children with confirmed H1N1 infection experience an uncomplicated viral illness. Nevertheless, underlying asthma and obesity may aggravate their clinical course.