Novel influenza A (H1N1): clinical features of pediatric hospitalizations in two successive waves

Summary 

Objective

To describe and compare the characteristics of children hospitalized with novel influenza A (H1N1) during two successive waves.

Methods

This was a medical chart review of all children hospitalized in a French Canadian pediatric hospital in Montreal in the spring and fall of 2009 with a positive real-time polymerase chain reaction for novel influenza A (H1N1) and flu-like symptoms.

Results

We included 202 children with a median age of 4.9 (range 0.1–18) years. Demographic and clinical features of the children in the two waves were similar. One or more underlying medical conditions were found in 59% of the children. Clinical findings at admission were: fever (98%), cough (88%), congestion/rhinorrhea (58%), gastrointestinal symptoms (47%), oxygen saturation below 95% (33%), sore throat (20%), and neurological symptoms (9%). Admission to the intensive care unit was required for 22 (11%) children, and 14 patients needed respiratory support. During the second wave, the median duration of stay was shorter (3 vs. 4 days, p=0.003) and oseltamivir was used more often (84% vs. 40%, p<0.001).

Conclusions

Children hospitalized during the two successive waves of H1N1 were mainly school-aged and suffered from moderate disease. Although clinical features and severity of disease were similar, oseltamivir was prescribed more frequently and the length of hospital stay was shorter in the second wave.

Keywords: Novel influenza A (H1N1), Influenza-related complications, Pediatric hospitalization