Report on the outbreak of the plague at Sydney, 1900 / by the Chief Medical Officer of the Government and President of the Board of Health.

Thompson, J. Ashburton (John Ashburton), 1848-1915.

Date:: 1900

Credit: Report on the outbreak of the plague at Sydney, 1900 / by the Chief Medical Officer of the Government and President of the Board of Health. Source: Wellcome Collection.

Provider: This material has been provided by King’s College London. The original may be consulted at King’s College London.

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$The two former can be certainly excluded witliout difficulty. The bacillus of plague can survive in ^vater for sliort terms, which vary with the kind of water used (sterilised, distilled, main, or sea water) ; this knowledge, however, has been gained experimentally (except one observation on sea water), and it has not yet been noted whether plague can be communicated to animals from water carrying plague-bacilli. What is more to the purpose is that wlnle the epidemic spread of plague by town water sujiplies has never been suggested, the accounts returned from several different parts of the world do not furnish the least ground for suspecti'ag that it may have happened. As regards Sydney, it is enongh to point out (a) that a very much larger area than that included hi Diagram A is supplied from one primary source ; {b) that while the water from this single sourca is pumped to, and distributed from, subsidiary reservoirs, more than one such i escrvoir must have been contaminated to account for the observed distribution of cases ; and (c) that Manly has its own source of supply, entirely distinct from the former. Secondly, as regards distribution of the infection by food in any form, it is now generally admitted that the disease is rarely communicated to man by feeding; there is no reason for suspecting that tliis mode can have been a factor in any epidemic prevalence of the disease hitherto observed. Remains, then, only habitual communication from person to person as a possible cause of the Sydney epidemic. This might be brought about directly or by mediate channels : the infection might pass directly from the sick to the well; or it might be communicated from the sick person to some place or object, whence the second patient could receive the disease without having seen, or even become aware of the existence of, the primary case. These are ways in which epidemics are known to be sometimes caused (of small-pox or scarlet fever, for instance). Whether they had any important share in contributing to cause the Sydney out])reak of plague is the question now to be examined. But, first, the difference there is between the possible communication of disease by one or other means realised only from time to time and rarely, and such a usual communication of it as alone can cause epidemic prevalences, must be referred to. All j)reventil)le disease shoukl be prevented ; and, therefore, if special dangers exist they should be guarded against by precautions specially taken against them. The first object, however, is to prevent epidemic prevalences; afterwards, the cccasional causes of exceptional occurrences of the disease can be considered and steps taken to prevent even them. In the first place, it may be inquired Avhether the facts furnish any reason for suspecting that infection mediately communicated from man was the cause, or an important contributory cause, of the epidemic. How could such mediate infection operate efFectively ? ^ nly by habitual diffusion of household goods. Only in this way could articles which had been in contact with, and which had received the infection from, the sick, be brought sufficiently often into contact with healthy persons; and such contact to have been a factor in the epidemic must have taken effect on persons outside the house occupied by the primary patient. Pirstly, then, the infected households were much the most often those of respectable Avorking-people who carried on no business at home, but who left home every day for some place of employment. These are not the people wdiose liousehold belongings are commonly liable to wide diffusion; but if they were, the suddenness with which this disease usually attacks must be remembered, and that it would be singular if the first few days of an illness which was almost always alarming from the first, were chosen for such diff'usion. Secondly, although in order to cause an epidemic spread of disease such com- munication must be between the primary household and others, yet, if it could take effect on the latter, much more should it take effect within th.e primary household itself; but it will be seen directly that only 10 altogether out of 276 households yielded secondary cases, and those occurred under circumstances so different that they cannot be classed together. If, then, mediate infection played so small a part (if any) within households, it could not have played a larger part outside them. One other possibility remains open, namely, unconscious diffusion of the infection by means of articles of commerce handled by the sick. Here, again, the sudden- ness of attack must be referred to. Persons did not, and, for the most part, could not, remain at work a moment after onset of the disease, and until then they were$