View report page

In the follow ing tables are shown the fatality (case mortality) of scarlet-fever and diphtheria
in each month of the year 1898 and in the period 1891-98. The rates are obtained by applying to
the number of cases notified in each month the deaths of a month beginning and ending a week
later, in order that, as far as possible, the deaths may be applied to the cases to which they belong. It
will be seen that the fatality of scarlet-fever is greatest at the beginning of the year, that it falls
with more or less regularity until September and October are reached, and that it subsequently
increases towards the close of the year. The fatality of diphtheria follows much the same course,
except that the figures suggest that the minimum will eventually be found to occur some two or
three months earlier than that of scarlet-fever. Fatality is necessarily affected by the age distribution
of the cases, but correction for such variation has shown (see annual report, 1895) that
variation in age and sex distribution does not suffice to account for the variation in fatality shown
in the tables. The following tables, however, show an interruption to the curve of fatality of
scarlet-fever and diphtheria in the month of August, due to the difference in the age distribution
of the cases in that month, the result of the closing of the schools for the holiday, when the cases
consist in larger proportion of young children whose fatality is higher than that of older children—