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132
Annual Report of the London County Councilt 1911.
Raising the lower limit of school age is a favourite proposition with people who write or speak
on measles. It has already been pointed out that Scotland, where the lower limit of school age is already
higher than in England, suffers a greater mortality from measles.
The contagion of measles is incurred by a young child, either (1) in the family from another
member, or (2) beyond the family.
In Figure 9 representing the probable distribution of measles cases at the earlier years
of life in London during 1909, as deduced from the mortality returns, the effect (1) is shown by the
ordinary form of curve rising to a peak and continued downwards in the thin curved line ; the further
effect (2), shown by a hump super-imposed on the curve in the fifth year, probably illustrates the effect
of contagion on entering school. It shows that children in their fifth year in about two-sevenths of
the cases occurring in 1909 may be supposed to possibly contract measles directly at school. The
number of cases in question represents between 5 and 6 per cent, of all the cases. If school was excluded,
the curve would probably be as in the thin line lower before about six to seven years old and more after
but the difference is probably not very great. If it is supposed that by excluding four year olds till
their fifth birthday these cases of school contagion could be prevented, this would mean postponement
of 5.2 per cent, of the cases, or taking the concrete example of 1909 in London it would be approximately
4,000 cases. As the case rate mortality at 4 to 5 is about 0.9 per cent., and at 5 to 6, about 0.7 per cent.,
the saving of life would be the difference ; that is 0.2 per cent., and for 4,000 cases this amounts to
8 cases. These avoided out of a total of 2,371 fatal cases for 1909 would mean affecting the measles
mortality by .03 per cent. If all the four to five-year-old children were kept out of school until they
were five, there would be a crop of fatalities from other causes such as deaths by violence in the homes
or motor vehicles, etc., in the streets outweighing any gain in measles mortality.
The indirect mortality through secondary infection of younger children in the home has to be
considered. Measles is regarded in this report as the disease which more than any other shows school
influence. For this purpose mere case notifications are unreliable, as the apparent school influence
shown in scarlatina or diphtheria notifications demonstrates. The mortality returns, however, are
Figure 10.—Deaths from measles, diphtheria, scarlatina, summed for ten years. Weekly deaths as mean
of three weekly average. London 1900-1910. (Miss L. D. Fairfield.) Measles, dotted line; Diphtheria, thin
continous line ; Scarlet Fever, thick line.
shown in Diagram 10, taken from a recent paper by one of our school doctors, to differentiate between
the school effect on these diseases. Both the summer and Christmas holidays show a prolongation
of the depression in measles mortality, and no noteworthy effect on the mortality of scarlatina or
diphtheria.
This school effect is, however, a result of excluding all children from school; but schools cannot
be entirely and constantly closed. The result of holding up the four to five year old children was