Effect of influenza epidemics on Australian mortality.

The effect of influenza epidemics on all major causes of death has been examined. The results showed an increase in total mortality, and a fall in life expectancy, during epidemic years. Using the 1974 epidemic as an example, an increase in mortality was found in all age groups, with the greatest percentage in increases occurring in the very young and the very old. For all ages combined, the greatest percentage increases in mortality were for respiratory diseases, while the greatest absolute increases in mortality were for cardiovascular diseases, especially ischaemic heart disease. A thrombotic mechanism is suggested to explain the increase in mortality from cardiovascular diseases.