Clinical and Laboratory Features of Hospitalized Children with Pandemic Influenza: Is it Different from the Other Respiratory Tract Infections?

Objective: To evaluate the clinical and laboratory findings of children hospitalized due to H1N1 virus infection with respiratory tract infection (RTI) during the last two months of 2009 and to compare patients in two groups: H1N1(+) and H1N1(-). Material and Methods: The data of 86 children with RTI, who were hospitalized between November 1 2009 and December 31 2009 at the Izmir Tepecik Training and Research Hospital Department of Pediatrics were reviewed retrospectively. Real time polymerase chain reaction (real time-PCR) was performed for all hospitalized cases. With this method, the H1N1 (+) and (-) cases were compared in terms of clinical and laboratory characteristics. Results: Forty-eight of 86 cases with RTI were H1N1(+). Older age (p=0.047) and underlying disease (p=0.043) were more frequent in H1N1(+) cases. A higher hemoglobin level (p=0.011), lower platelet count (p<0.001) and reduced incidence of a high C-reactive protein (CRP) level (>0.8 mg/dL) (p=0.004) were determined in the H1N1(+) group. Lobar infiltration determined by chest X-ray was less frequent in the H1N1(+) group (p=0.002). One patient died the in H1N1(+) group. There were no significant differences between the two groups regarding the length of hospital stay, frequency of pediatric intensive care admission and mortality rate (p>0.005). In the logistic regression analysis, hemoglobin level (p=0.033), high CRP (>0.08 mg/dL) (p=0.005) and the incidence of lobar infiltration by X-ray (p=0.036) were found to be significant parameters distinguishing the H1N1(+) and H1N1(-) groups. Conclusion: Pandemic Influenza affected children in the older age group with chronic medical conditions.The length of hospital stay, the rate of admission in the pediatric intensive care unit and the mortality rate were not different in H1N1(+) and H1N1(-) children.