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

PubMedID: 21859378Background: 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 admitted or transferred to the paediatric intensive care units (PICU) and 52 (6.3%) received mechanical ventilation. Thirty-five children (4.3%) died. The mortality rate did not differ between age groups. Of the patients who died, 25.7% were healthy before the H1N1 virus infection. However, the death rate was significantly higher in patients with malignancy, chronic neurological disease, immunosuppressive therapy, at least 1 pre-existing condition, and respiratory complications. The most common causes of mortality were pneumonia and sepsis. Conclusions: In Turkey, 2009 H1N1 infection caused high mortality and PICU admission due to severe respiratory illness and complications, especially in children with an underlying condition. © 2011 Informa Healthcare.Ankara Universitesi Medical School, University of Michigan 7Pediatric 5Pediatric Faculty of Medicine, Assiut UniversityFrom the 1Department of Pediatrics,Ankara University Medical School,Ankara,Turkey,2Department of Pediatric Infection Diseases,Dr.Sami Ulus Maternity and Children Training and Research Hospital,Ankara,Turkey, 3Department of Pediatrics, Republic of Turkey Ministry of Health Ankara Dıs¸kapı Children’s and Research Hospital, Ankara,Turkey, 4Department of Pediatrics, Ondokuz Mayıs University Medical School, Samsun,Turkey, 5Pediatric Infectious Diseases Unit,Dr.Behçet Uz Children’s Hospital,Izmir,Turkey,6Division of Pediatric Infectious Diseases,S¸is¸li Etfal Training and Research Hospital, Istanbul,Turkey, 7Pediatric Infectious Diseases Unit, Department of Pediatrics, Hacettepe University Faculty of Medicine,Ankara,Turkey,8Division of Pediatrics,Adana Numune Research and Training Hospital,Adana, Turkey,9Department of Pediatrics,Gazi University Medical School,Ankara,Turkey,10Department of Pediatrics,Selçuk University Meram Medical Faculty, Konya,Turkey, 11Department of Pediatrics and Pediatric Infectious Diseases, Uludag^ University Medical School, Bursa,Turkey, 12Clinics of Pediatrics,Tepecik Training and Research Hospital, Izmir,Turkey, 13Division of Pediatric Infectious Diseases, Department of Children’s Health and Diseases, Çukurova University Faculty of Medicine,Adana,Turkey,14Department of Pediatrics,Eskis¸ehir Osmangazi University Faculty of Medicine,Eskis¸ehir, Turkey, 15Pediatric Infectious Diseases Unit, Department of Pediatrics, Süleyman Demirel University Faculty of Medicine, Isparta,Turkey, 16Department of Pediatrics, Marmara University Medical School, Istanbul,Turkey, 17Department of Pediatrics,Mersin University Medical School,Mersin,Turkey,and 18Department of Biostatistics,Ankara University Medical School, Ankara, Turke