A severe influenza season in Austria and its impact on the paediatric population: mortality and hospital admission rates, november 2017 - march 2018.

BACKGROUND

In Austria paediatric influenza-associated hospitalisations and deaths have never been systematically monitored. We examined the influenza season 2017/18 in terms of hospitalisation and mortality in the Austrian paediatric population and put the results into perspective of the available data from the last 15 years.

METHODS

Cases of influenza-associated hospitalisations and deaths for season 2017/18 in children below 18 years were retrospectively collected from 12 and 33 Austrian hospitals, respectively. Hospitalisation and mortality rates for the whole Austrian paediatric population were estimated, adjusting for the population in each catchment area. Two Austrian databases were queried for hospitalisations and deaths associated with influenza during 2002-2016. Rough estimate of the vaccination coverage was calculated from a survey on 100 inpatients.

RESULTS

Influenza-related paediatric hospitalisation rate in season 2017/18 was estimated as 128 (CI: 122-135) per 100,000 children, much higher than the national average of 40 per 100,000 over the years 2002-2016. There were nine reported influenza-associated deaths among children, resulting in mortality rate of 0.67 (CI: 0.32-1.21) per 100,000 children.

CONCLUSIONS

Reported influenza-associated hospitalisations and fatalities demonstrate a high burden of influenza in the Austrian paediatric population corresponding with very low vaccination coverage.