H.—3l

28

Chart A. — Showing Deaths from Influenza daily during Epidemic.

It, will be seen from this that there was a very steady increase in mortality from the first week in October onwards; that it was not till the week ending the 4th November'that the epidemic deathrate could be said to be established; that it rose rapidly in the first three weeks of November and reached its peak in the week ending 25th November, and then declined as rapidly as it began. The incidence is well illustrated in Chart A (attached). Probably were the actual incidence of the disease known the peak representing the greatest number of cases would be a week or so before the highest death-rate, but on this point we have no accurate information save the Camp sickness returns, which, show the 9th November as the highest date of incidence. The disease spread very rapidiv in the camps, and, like the North Island generally, began there earlier than the mean for New Zealand. We can then take the week ending the 18th November as representing the average peak wave of incidence for the whole Dominion. It is of interest to compare the above figures with the following table, showing the deaths from influenza in the ninety-six largest towns in England : — Table XII. Week ending October 19 .. .. .. .. .. ..1,895 „ 26 .. 4,482 November 2 .. .. .. .. .. .. 7,412 9 .. .. '.. .. - .. .. 7,560 16 5,916 23 ' .. .. 5,106 The crest of the secondary wave in England was then almost identical in date with that in New Zealand, a fact not without significance, and one to which further reference will be made. It is possible now to sketch the general incidence of the two waves throughout the world. The first wave began among the troops on the western front about April, spreading rapidly thereafter in Europe and America. It began to be epidemic in Britain in May, and reached its peak there in July. It began to be epidemic in New Zealand in July, and reached its peak in September. It then followed the usual course of an epidemic, spreading along trade routes — the delay of two months between the appearance in Britain and that in New Zealand representing the period which one would naturally expect would be occupied in its conveyance to the Antipodes. The second wave did not follow the usual course of spread of an epidemic wave round the world, but began somewhat irregularly to appear among shipping at the end of August (i.e., trans ports " Tahiti," " Chepstow Castle," and " Mantua " at Sierra Leone), and in localized outbreaks in Glasgow and other ports, anil in the eastern States of America in September. It is not. easy to fix exact dates, but definite explosive outbreaks appear to have been established somewhat as follows : — Last weeks of September .. .. Spain; Paris; Portugal. End of September and first week of October .. . ■ ■ • Cape Town ; Quebec ; Boston, U.S.A. First and second weeks of October .. British Expeditionary Force (western front) ; Eastern Canada ; "Natal ; Italy ; Greece. Third and fourth weeks of October .. Switzerland ; Holland ; Washington ; New York ; Sweden. Last weeks of October and first week of November .. .. ■. Britain ; western America ; New Zealand ; Peru ; Denmark. During November .. .. India ; China.