Sessional_Paper_1904 — Page 758

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Thus we see that apart from the season of the year, epidemic plague appears to be preceded by epizootic plague, and that the interval of time between the out- breaks varies from ten days to a fortnight.

WILLIAM HUNTER.

The History of Health District No. 1 in 1903.-A close examination of the curves shown upon the chart prepared from this district will show how closely the two curves follow each other. at plague was existent at the commencement of the year. It rose in February. During January and February there was no human plague. In March, however, this appeared.

The general history of the curves is so simply given in the chart that further explanation is considered unnecessary. Note should be made of the disappearance of rat plague for practically the whole of the second half of the year.

The History of Health District No. 2 in 1903.-In my opinion this is an excellent chart for purposes of demonstrating the relation between human and rat plague.

The gradual rise in the epizootic followed closely by a gradual increase of cases of human plague. The primary decline in the epizootic followed by a lower- ing of the epizootic. The disappearance of rat plague followed by a disappearance of human plague.

Noteworthy is the complete immunity of the district during the last two months of the year,

The History of the Course and Relations of Epizootic and Epidemic Plague during the Initial Stages of the Outbreak of 1904.

The unexpected delay in the preparation of this report has enabled me to follow out the initial outbreaks of epizootic and epidemic plague for the year 1904.

No special charts have been prepared, but a good idea of the condition of affairs may be ascertained by consulting the chart dealing with the interval bridg- ing over the epidemics of 1903 and 1904.

During the first week in January it will be seen that rat plague was present to a considerable extent in the Colony. The epizootic rose step by step until the beginning of February, when a rather erratic jump upwards took place. This sudden increase in the amount of rat plague was followed by the appearance of human plague a week later.

The exacerbation in the epizootic lasts only a fortnight. The number of cases per week fell considerably but did not reach the level of the epizootic previous to the sudden increase. The curve occupied now a higher level on the chart and remained more or less constant for about two months. During this period, human plague put in an appearance from time to time.

The definite increase in the number of cases of rat plague commenced about the beginning of April, and this was followed by the appearance of human plague in epidemic form.

On following the curve of the epizootic, through the month of January and the first half of February, ominous signs are present. Cases of human plague appear and the condition of affairs resembles that found at the beginning of 1903. Fortunately a decided fall in rat plague took place, and the new but more elevated position of the epizoctic maintained itself weekly without further exacerbations for about 8 to 10 weeks. Human plague practically disappeared, and did not assert itself again until the epizootic broke out afresh and in continued exacerbation. Looking generally at the epizootic curve, one can see a general tendency to increase. If we compare it with that of 1903, we find a great postponement in the increase of rat plague and the occurrence of the epidemic.

WILLIAM HUNTER.