Burden of disease

Seasonal influenza represents a year-round disease burden. It causes illnesses that range in severity and sometimes lead to hospitalization and death.

Tools to measure influenza disease burden

WHO has published a manual on how to estimate influenza disease burden, the economic burden plus a supplement on how to estimate the denominator. Also find the link to online training on the tools.

Importance of measuring influenza burden of disease

Country disease burden estimates play a crucial role in helping to address the threat of seasonal, strengthening national and global preparedness, prevention and control efforts and understanding the overall global burden of influenza disease and prepares for influenza pandemics. However, despite an increase in the number of countries producing estimates to inform influenza prevention measures, gaps still remain such as a lack of high quality and up-to-date estimates of severe influenza burden at global and regional levels; relatively few low and middle-income countries (LMICs) that have developed reliable national estimates of influenza burden of disease (BoD); and a lack of reliable BoD data and on the possible impact of vaccination among specific high-risk groups.

WHO continues to support countries in generating national estimates.

Estimate of influenza deaths due to respiratory disease

WHO estimates that seasonal influenza may result in 290 000-650 000 deaths each year due to respiratory diseases alone.

The estimate does not take into account deaths from other diseases such as cardiovascular disease, which can be influenza-related. Further surveillance and laboratory studies of all influenza-related diseases are ongoing and are expected to yield sustantially higher estimates over the next few years. The implications of the estimate , highlights the scale of the threat of influenza at a national and global level and re-enforces the need for countries to take action to address their influenza disease burden.