141
A study of the foregoing Table shews that the percentage mortality is high at all the age-periods but especially high in males between 51 and 60 years, and between 66 and 70 years. In females it is high from 6 to 15 years, then there is a drop in the next 5-year period, a gradual rise from 21-25 which continues into the next quinquenniad. After this the percentage is very high from 31-45 years of age, and then there is a noticeable drop during the period 46-50 followed by a rise from 51 to 55. In the next three quinquenniads the percentage reaches 100, after which it drops to 50 during the period 71-75.
It would thus be seen that the mortality percentage rules high in adult life, and that the disease especially among females is very fatal in the more advanced periods of life, the capacity of resistance among them decreasing with advancing years.
Incidence with reference to Occupation.
We append a Table No. VI in which we have analysed the occupation of the patients in the case of inales 2,710, and females 197.
A very large majority of cases occurred among the coolie class, of whom 878 were relieved and 857 died. Under the heading Workman" 178 were treated, 88 being relieved and 90 died. This term refers simply to those employed in manual unskilled labour. Masons come next in the list, numbering 165, of these 86 were relieved and 79 died. Seamen constitute a fair number-59, with 29 deaths and 30 recoveries. Hawkers constitute a large proportion-79, of whom 30 were relieved and 49 died. Carpenters, Boatmen, Barbers all contribute a fair share, and so do Tailors, Rattan-chair makers, Servants and Cooks. Other trades and occupations furnish a very small proportion of cases.
The list serves
to shew that practically no trade is exempt from the disease. From a consideration of the Table we may draw the following inferences :-
(1.)—That the disease is universally prevalent among the community.
(2.)-That it especially affects the working classes.
(3.) That the professional classes, leisured classes and merchants are practically exempt, though a case here and there testifies to inference- (1) above.
The total number of coolies almitted amounted to 1,730 constituting a per- centage of nearly 60. It is well known that their surroundings, domnestic and otherwise, and their food and habits, are not altogether unexceptionable. Gene- rally they are crowded together at work and in the house, natural sanitary laws are set at defiance, their personal habits are unclean, their food is of the poorest quality and the cheapest. In all Beri-beri countries these are the conditions which obtain among those that contract the disease. We are compelled, therefore, to regard them as having a causative relation to the disease in the direction of predis- position; a similar statement may be made with reference to other classes, especially
of workmen.
The Question of Contagion and Infection.
Froni
From our observations we are of opinion that the disease is neither contagious nor infectious-(vide Part III). When a case is removed from any locality, say for instance some institution where the disease has appeared, and is freely allowed to go among other people, we have not seen any cases develop.
Cases are con- stantly taken into the wards of a General Hospital but no fresh cases arise. facts like these and from the result of our experimental work we are of opinion that the evidence against contagion and infection is very strong. Cases are some- times produced which are stated to refute this statement, but the underlying fallacy in these is one practical ignorance of the length of the period of incubation.
Length of Exposure before Manifestation of the Disease.
This varies within wide limits. We were able to calculate this
We were able to calculate this very exactly in the outbreak which occurred in the Po Leung Kuk. The first two cases occurred on May 14th. The inmates who were admitted into the Institution, (and who were all found to be healthy on examination), after this date-May 14th-were obviously