(1) There were nineteen cases and eight deaths at the depot during the epidemic.
One doubtful case during this period recovered, and a sporadic case in June due to Type I also recovered; these are not included in the above, nor is one man who went on leave to Blackpool, and developed the disease (Type II) on arrival.
(2) So far the reserve battalions have had three cases only, with two deaths, although a high carrier-rate wave has been detected in two.
(3) All the cases (except the June case) at the depot occurred during exceptionally cold weather. In the chart the cases appear to lie in thetrough of a great depression of the curve of mean weekly temperature (broken line). They also follow immediately upon exceptional crowding (black line).
(4) There was a well-marked premonitory rise in the carrier-rate in December 1916, before the first case occurred, and an enormous rise before the epidemic was really established.The carrier-rate, which was 19·25% on December 23rd, reache dwhat is usually considered the danger point of 20% (see War OfficeMemorandum on Cerebro-spinal Fever, page 2) just six days before the first case occurred.
It would appear that estimations of the carrier-rate by means of large sample swabbings afford a reliable warning of the imminence or danger of an epidemic.
(5) The cases in the epidemic were nearly all due to the meningococcus of Type II, the organism present in the outbreak of 1916.
The rise in the carrier-rate was also chiefly due to the increase ofcarriers of this type. Freshly joined recruits showed few carriers at all and very few Type II carriers when swabbed before having slept in the barracks.
(6) During the epidemic, the carrier-rate among non-contacts was substantially the same as amongst the actual contacts of cases, averaging34% for the period, in each case.
(7) The proportion of agglutinable strains to inagglutinable strains of organisms morphologically indistinguishable from the meningococcus increased very markedly during the epidemic period.
(8) The treatment of the whole population by the steam zinc sulphate solution spray (which was carried out daily for two seven-day periods with an interval of a fortnight), was followed by a satisfactory drop in the carrier-rate, and by a temporary cessation of cases on each occasion.
(9) 60% of the actual patients suffering from the disease were in their first month of service.
40% of the patients had either been inoculated or vaccinated within seven days of onset (three on the same day); 60% within afortnight.
(10) Previous and concurrent epidemics of German measles, influenza and bronchitis had helped (by causing coughing and sneezing and by lowering vitality) to produce the great rise in the carrier-rate, which culminated in the case epidemic.