LAUSR

Aims Severe complications and deaths due to influenza in children were reported during the 2009 influenza pandemic, but there are few reports for non-pandemic periods. We aimed to address this gap in knowledge by describing severe outcomes of influenza among Australian children from 2008 to 2016. Methods We conducted surveillance through the Australian Paediatric Surveillance Unit (APSU) during July to September each year, for children aged <15 years, admitted to hospital with severe complications of laboratory proven influenza. Results A total of 489 cases were reported: median age=3 years (0–14.8) and 56.5% were boys. Most 338 (69%) had influenza A. Complications included pneumonia (61.2%), encephalitis (13.3%), myocarditis/pericarditis (3.7%), shock (3.9%), rhabdomyolysis (3.9%). Viral or bacterial co-infections were reported in 18%. Of the 489 children 24 (5.3%) were vaccinated for influenza and of 174 of children who had chronic conditions pre-disposing for influenza 15 (8.2%) were vaccinated. There were 21 deaths. Deaths occurred in each year of surveillance except for 2016, and in 52.3% the children had a pre-existing condition (e.g.rare genetic syndromes, cerebral palsy, ulcerative colitis), but 47.6% of children that died were previously healthy. Given that almost half of the children who died were previously healthy, there is a need for rapid diagnosis and treatment of children with severe complications of influenza, and all children should be vaccinated for influenza,not just those who have underlying chronic conditions. Conclusions Awareness raising and education about early diagnosis and treatment in addition to increasing annual influenza vaccination is neded among health professionals caring for children children whether or not the children have pre-disposing medical conditions. Ongoing surveillance is needed to monitor the effectivenes of vaccination programmes to prvent these seious outcomes of influenza infection in children.