Pandemic H1N1 in children requiring intensive care in Australia and New Zealand during winter 2009.

OBJECTIVE

To describe in detail the pediatric intensive care experience of influenza A, particularly pandemic H1N1-09, in Australia and New Zealand during the 2009 Southern Hemisphere winter and to compare the pediatric experience with that of adults.

METHOD: This was an inception-cohort study of all children who were admitted to intensive care with confirmed influenza A during winter 2009 at all general ICUs and PICUs in Australia and New Zealand.

RESULTS

From June 1 through August 31, 2009, 107 children (20.0 per million [95% confidence interval: 16.1-23.8]) with influenza A, including 83 (15.5 per million [95% confidence interval: 12.1-18.9]) with H1N1-09 were admitted to ICUs. Fifty-two percent (39 of 75) of children with H1N1-09 had 1 or more comorbidity, most commonly neurologic (20%). Most (48 of 83 [58%]) presented with pneumonia. Thirteen of 83 (16%) had neurologic presentations. Eighty percent of the children with H1N1-09 required ventilation. Mortality was lower than in adults: 6 of 83 (7%) vs 114 of 668 (17%) (P = .02). The median length of stay for children with H1N1-09 was 5 days. Children with H1N1-09 occupied 773 bed-days (147 per million children) and 5.8% of specialist PICU beds. Presentation with septic shock or after cardiac arrest and the presence of 1 or more comorbidities were risk factors for severe disease.

CONCLUSIONS

H1N1-09 caused a substantial burden on pediatric intensive care services in Australia and New Zealand. Compared with adults, children more commonly had nonrespiratory presentations and required ventilation more often but had a lower mortality rate.