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The proportion of children in the hospitals who have attended schools within seven days of
attack must vary very much. The fact that the six months selected include the Easter holiday and
especially the summer holiday, when the disease has a natural tendency to be prevalent, would lead to
increase in the proportion of children in the hospitals who have not attended school within seven days
of attack. If the figures of the first and second three months had been given separately, the results
in the two periods would probably have been very different.
The proportion of children aged 3-4 attending school is, as I have already said, 110 doubt small,
but the natural incidence of the disease at this age is great. It would be interesting to learn how
many of 261 cases at this age, shown by Dr. Smith in his Table XXXI. to have been removed to
hospital, are included among the 545 cases which did not attend school within seven days of attack.
He next summarises the results of his inquiry as follows—
Cases concerning which full information could not be obtained 47
Cases in which no source of infection could be discovered 1,618
Cases in which infection was traceable directly or indirectly to school 124
Cases in which infection was traced to a school-attending child, and casting,
therefore, some suspicion on the school 55
Cases in which infection was traceable to other sources than school 324
2,168
He states that "in only 124 cases can the disease be fairly attributed to school influence, or only
"in 5.7 per cent. of the whole." It may be pointed out that of the total number of cases in which the
cause of infection could be traced—viz., 503—124 were distinctly traceable to school, or 24.6 per
cent. With regard to the 1,618 concerning which no source of infection was discoverable, it would have
been fair to have assumed that some proportion, perhaps the same proportion, was also due to schools;
but Dr. Smith subsequently appended a note to his report that "no enquiry was made into
"the 2,168 cases referred to on page 31, with the view of ascertaining the cause of infection, beyond
"the point of determining whether school influence had in any way existed. In 324 cases, however,
"a source of infection other than school influence was obvious."
The reader is therefore obliged to assume that the 1,618 cases in which "no source of infection
"was discoverable" are to be interpreted as being cases in which no source of school infection was
discoverable, and if this be the case it is difficult to understand why any distinction is made between
these 1,618 cases and the 324 cases which were "traceable to other sources than school."
It is especially difficult to understand the amount of importance to be attached by the reader
to these 324 cases if, as may be understood by Dr. Smith's later note, this number might be considerably
augmented at the expense of the 1,618 cases, had more detailed enquiry been made into the
source of infection; for Dr. Smith uses these figures for the calculation of a percentage which,
considered in the light of his later note, must be regarded as valueless for comparative purposes. Thus,
he writes—
"On the other hand 324 cases are traceable to other sources, to which number should probably be
added the 55 cases traceable to school-attending children, as the most careful enquiry failed in each of
these cases to throw any suspicion upon the school itself; nearly 15 per cent. of the cases are traceable
to other sources, and if we include the above 55 cases, the percentage becomes nearly 18."
In an endeavour to understand what is meant by the words "traceable to school" the reader
of Dr. Smith's report will observe that his enquiry of school teachers includes the question whether
any children in the same class-room as a child who had been attacked by diphtheria had suffered from
any throat affection during the fortnight before the affected child's illness. His report gives no
information as to what, if any, course was adopted for discovering throat illness other than recognised
and certified diphtheria in other classes of such school. The question assumes larger importance when
Dr. Smith's report on an outbreak of diphtheria in Lewisham in 1896, which had been investigated by
Dr. Hamer, is considered. Dr. Smith's method of dealing with this subject led me on that occasion,
in commenting on his report, to make the following observations—
"By excluding, save in a trifling number of instances, any consideration of the effect which may be
produced on a child suffering from diphtheria on his schoolmates, who do not actually happen to share
the same class-room with such child, he reduces the number of cases which may be reasonably thought
of as school-infected.
"In this manner he excludes from the number of children who may be reasonably thought of as
school-infected, every child who is the first recognised sufferer from disease in its class-room. Thus inasmuch
as 14 or 15 class-rooms in the schools above referred to were infected, this number of cases of
diphtheria is included among his 'cases in which the evidence excludes the school as a source of
infection.'"
In conclusion, I desire to add that in my examination of the report of the medical officer of the
London School Board, I am unable to find a single point which militates against the views I have
expressed, or which would in my opinion justify the conclusion that the part played by schools in connection
with the increase of diphtheria is " unimportant."
Summary.
The influence of schools in disseminating infectious disease has been long recognised, and in
respect of diphtheria was shown, as early as 1876, by Mr. W. H. Power. There is therefore no
improbability in the suggestion that with increasing school attendance and corresponding increase of
opportunity of infection at school, that the result should be manifested in increased incidence of
diphtheria mortality upon children at the school age. The figures contained in this report show that
this increased incidence has actually occurred, and, although some part of it is probably attributable
to change in nomenclature, there is, I submit, a substantial balance due to this greater opportunity
of infection at school. This change in the age incidence of mortality had its beginning about the time