A University of Otago, Wellington study estimating influenza-associated deaths from 1990 to 2008 found that the majority of deaths (86%) occurred in those aged 65 years and over.
Lead author Dr Tara Kessaram says the results show the large public health impact of influenza, particularly among the elderly, many of whom will have underlying conditions that are triggered or made worse by influenza.
“Although pandemic influenza gets a lot of justified attention, we need to keep remembering the huge toll from seasonal influenza, which comes around each year,” Dr Kessaram says.
University of Otago, Wellington’s modelling shows that estimated mortality varied widely from year to year, ranging from 31 deaths in 1991 to 898 deaths in 2003. These differences reflect a number of factors including the virulence of the dominant circulating strain, Dr Kessaram says.
High mortality years tended to be those dominated by the influenza A(H3N2) subtype, she says. Despite these year to year variations, the overall mortality rate did not appear to show any downward trend over the study period.
Co-author Professor Michael Baker says statistical modelling is needed to estimate the impact of infl