Clinical and epidemiological features of Turkish children with 2009 pandemic influenza A (H1N1) infection: Experience from multiple tertiary paediatric centres in Turkey

AbstractBackground: In April 2009 a novel strain of human influenza A, identified as H1N1 virus, rapidly spread worldwide, and in early June 2009 the World Health Organization raised the pandemic alert level to phase 6. Herein we present the largest series of children who were hospitalized due to pandemic H1N1 infection in Turkey. Methods: We conducted a retrospective multicentre analysis of case records involving children hospitalized with influenza-like illness, in whom 2009 H1N1 influenza was diagnosed by reverse-transcriptase polymerase chain reaction assay, at 17 different tertiary hospitals. Results: A total of 821 children with 2009 pandemic H1N1 were hospitalized. The majority of admitted children (56.9%) were younger than 5 y of age. Three hundred and seventy-six children (45.8%) had 1 or more pre-existing conditions. Respiratory complications including wheezing, pneumonia, pneumothorax, pneumomediastinum, and hypoxemia were seen in 272 (33.2%) children. Ninety of the patients (11.0%) were admitt...