INFLUENZA IN AUSTRALIA

Sun (Christchurch), Volume VII, Issue 2126, 7 December 1920, Page 8

INFLUENZA IN AUSTRALIA

DEATHS IN TWO YEARS, £14,528.

Interesting information concerning the influenza epidemic of 1918-10 is contained in the Commonwealth Tear Book, which has just been issued by the Statistician (Mr G. H. Knibbs), says the "Argus." The total number of deaths caused by influenza during the period of the epidemic in Australia was 11,989, or 233 per 100,000 of population. There were marked epidemics of influenza in 1891, 1894-5 and 1899, but the recent visitation was much more severe than its predecessors. The annual declth rates per 1,000,000 persons from influenza during the period of 14 years from 1880 to 1893, 13 years from 1894 to 1906, and 12 years from 1907 to 1918, were 104, 202 and 98, respectively, while the rate for 1919 alone was 2331, or 23.8 times that of the average for the 1907-18 period. The association of pneumonia and heart disease with influenza was conspicuous in the epidemics of 1891 and 1919, and the deaths, as recorded as due to influenza and pneumonia influenza, show that, on the whole, these two causes are closely related.

The characteristics of the age incidence of the epidemic are sharply distinct from those of ordinary influenza. While in the mortality from ordinary influenza it continually increases with age for both males and females after the age of about 12} years is passed, in the pneumonic form it reaches a maximum—about 6300 —at the age of 36.4 years for males, and about 3700 at the age of 32.6 for females. The masculinity. of death from influenza is also peculiar. If the excess of males over females in 10,000 persons be ascertained, this number may be termed the masculinity per 10,000. Mr Knibbs presents statistics to show that for influenza the masculinity (as defined) greatly increases in 1919; for bronchopneumonia it distinctly increased over its value for 1918, though it was less than for the period 1907 to 1917; for pneumonia itself it greatly diminished, while for heart disease it did not greatly change. The number of deaths attributable to the epidemic of 1918-19 involves an analysis of the mortality from all diseases, and of the mortality from influenza in normal circumstances, owing to the supposition that many persons who died from influenza would have died if no epidemic had occurred. Adjusting these mortality figures, Mr Knibbs shows that there were 14,528 deaths during 1918-19 (comprising 590 in 1918, and 13,938 in 1919) more than would have normally occurred. This number was the death tribute for the two years owing directly and indirectly to the epidemic, on the assumption that the increase in deaths from pneumonia and heart disease were associated more or less direcfly with the influenza mortality.