11

H-.—19:

Featherston Gamp. —ln Featherston Camp the first wave was in August (403 cases), then followed a slight drop in September (326 cases), with a rise again in October (458 cases), but towards the end of October the spread appeared to lessen till the arrival on the 24th and 25th October of aCI draft. Of this draft, 126 men came from Auckland, and among these on the 26th 10 cases of influenza were reported, though not of a specially severe type at the time, and for the first week after their arrival there was no general epidemic among these men. The table following shows the daily incidence of influenza according to unit at the end of October and the beginning of November : —

Note.—Cl men mobilized on the 23rd, 24th, and 25th October.

This indicates clearly that the CI draft suffered most heavily at this time, and further evidence is found that this was the source of the severe infection in the fact that on the 29th October the first of the pneumonic cases occurred in this draft, the patient being a man who arrived from Auckland in camp on the 24th October. Since the incubation period is about forty-eight hours it is evident that this man did not himself contract the infection in Auckland or on the journey down, but probably was infected from the earlier cases developing after arrival in camp. Again we find that, amongst the first 219 eases of the severe wave, 39 per cent, came from Auckland Province. A large number of troops, including many from Auckland, had returned from leave on the 23rd October, yet their return did not result in any special wave of infection, suggesting that the epidemic in Auckland at the time of their departure (23rd October) was not yet severe. It must be noted that in the crowded troop-trains there is every facility for the rapid transference of disease throughout the troops, and experience with measles and cerebro-spinal meningitis has shown that troop-trains are fertile sources of infection. The absence of severe infection in these units on the 23rd October is therefore significant. This also applies to the CI draft arriving on the 24th and 25th October, who did not show any special spread at first, although 127 had made the long journey from Auckland in such close contact that had the disease been as infective as it became a week later they must have shown perhaps 50 per cent, of infection within a day or so of arrival in camp. The above table shows that on the Ist, 2nd, and 3rd November the epidemic was slowly gathering force, but the 4th November is given by the Principal Medical Officer as the date when the secondary wave was definitely established. This coincides with the return of the men from week-end leave, and doubtless the train journey'had much to do with the dissemination of infection from the earlier cases. The spread from then onwards was extraordinarily rapid, and the wave reached its maximum intensity on the 7th November, on which day over 400 new cases were reported. Thereafter there was a steady decline in the incidence, and the epidemic was over on the 20th November, as shown in the following table, only two or three oases per day being thereafter reported :— Date. Cases. Date. Cases. October 28 .. ' .. .. 12 November 10 .. .. ..- 257 29 '-.. ..10 11 .. .... ..274 30 .. ..14 12 .. .. ..149 31 .. .. ..10 13 .; .. . ..- 95■ ... 14 .. .. 99 Total .. .. ... 46 15 ... .. ..104 16 .. '"..•'■ ..49 November 1 .. .: .. 38 . 17 .. .. .. 44 d 2 .. ..48 18 - '~ --"...; .. 41 3 .. 69 19 .. ..,'. ..30 .. 4 .. .... 149 20 ... .. - ...... 22 '■'.:".:, 5 .. .. ./ 149 21 .. ■■-.;■■ 12 '■'■'■" 6 .. ... ..395 22 .. ..... 8- ~: 7 .. .. '..418 ' • ■■■■•' ■ 8 .. .. :. 371 Total .. .. .. 3,165 9 344

October. November. Unit. 26th. 27th. 28th. 29th. 30th. 31st. 1st. 2nd. 3rd. 4th. Total. 46th 47th 48th N.Z. Field Artillery .. N.Z. Mounted Rifles .. Specialists CI N.Z. Medical Corps .. Home Service 1 2 1 2 1 2 1 10 1 2 1 1 1 3 3 1 2 1 2 4 1 12 2 2 13 5 1 6 4 2 8 2 3 L8 8 2 14 13 5 1 3 25 4 1 20 37 3 7 3 16 38 10 3 53 62 6 39 11 26 129 27 7 3 1 7 5 5 5 Daily total 17 5 10 13 10 K) 53 66 137 360