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35
Report of the County Medical Officer—General.
Board, in those of Drs. Dunn and Bond, and perhaps in Belfast and Glasgow also, it was really influenza
with special involvement of the nervous system that was in question. Further reasons for insisting upon
the close inter-relationship existing between influenza and cerebro-spinal meningitis were given at the discussion
on cerebro-spinal meningitis reported in the Proceedings of the Royal Society of Medicine, March,
1915. Reference was then made to Sydenham's account of the "new fever," as he termed it, of 1685, and
the attempt was made to draw a parallel between this disease and the disease prevailing 230 years later
in the same city. In both years 1685 and 1915, there was considerable augmentation of the number of
deaths in London, but a few only of the patients presented nervous symptoms or eruptions, in many,
instances throat and lung troubles predominated, and in the latter year the Registrar General's Returns
included excessive numbers of deaths from bronchitis, pneumonia and influenza as well as from cerebrospinal
fever. It may be argued, with some reason, therefore, that if reliance be placed exclusively upon
bacteriological findings there is apt to be failure to see the wood because of the trees; and that the germs
to which such very great importance is attached may be merely after all "associated organisms" or
"secondary invaders." If the epidemiology of cerebro-spinal fever were regarded from a broader point of
view, it was, indeed, urged that it " would be possible to attain to more philosophical notions with
regard to its setiology, to more rational ideas as regards its prevention, and there might, too, be more
hope in respect of treatment than can apparently be entertained in the light of popularly accepted
theories."
The opportunity presented itself on the occurrence of the recent epidemic of putting these suggestions
to the test. During the first ten months of 1914, scattered cases only of cerebro-spinal meningitis
were reported in London, then at the end of the year came the outbreak of influenza, pneumonia,
bronchitis, etc., and close on its heels the prevalence of cerebro-spinal fever. The time relations of
the outbreaks are shown on the accompanying diagram (W).
It will be seen on referring to diagram (X) that the deaths from influenza reached a maximum in
the eighth week of the year 1915, the deaths in the ninth week sharply declined and this was followed by an
increase in the deaths of the tenth and eleventh weeks, after which the deaths progressively diminished.
The notified cases of cerebro-spinal fever rose in the sixth and seventh weeks of the same year, reached
a higher level in the ninth, tenth, eleventh and twelfth weeks, attaining a maximum in the fourteenth
and fifteenth weeks, after which the numbers steadily diminished. It will be seen from the diagram
that the cases of cerebro-spinal fever reached a notably high level in the week following that showing
the maximum mortality from influenaa. Diagram (X) shows the time relationships of the two diseases
for the period 1908-13.
With a view to throwing further light on the question of possible inter-relationship between
these two diseases the information obtained from borough medical officers of health concerning cases
of cerebro-spinal fever has been utilised for the purpose of ascertaining the number of cases giving a
history of recent attack by or contact with cases of influenza. As a result it appears that of 61 patients
notified during the year 1914, concerning whom particulars were obtained, 12 gave a history of having
recently suffered from colds; and contact with cases of influenza, cold or sore throat was noted in 4
cases. During the period 1st January to 22nd May of the year 1915, however, when influenza was
prevalent, 523 cases of cerebro-spinal fever were reported and among the 462 cases concerning which
particulars were obtained there was a history of recent influenza in 37 instances, and in 27 of these the
patient was said to be suffering from influenza within 7 days of the onset of symptoms of cerebro-spinal
fever. Colds, sore throat, cough and catarrh were noted as having affected 70 patients prior to attack
by cerebro-spinal fever and ten patients had recently suffered from pneumonia. Contact with
cases of influenza colds, etc., was noted in 66 instances.
The number of cases giving a history of recent attack by or contact with cases of influenza is
certainly large enough to afford justification for further examination. The main point to be determined
is whether the number of cases of cerebro-spinal fever giving a history of (a) recent attack by, and
(6) contact with, cases of influenza is greater than might have been expected as a matter of chance. The
determination of the probability of the occurrence of (6) would necessitate the use of some hypothetical
figure which would represent the average number of persons coming into association with the average
Londoner in the course of a week. It is obvious that the use of such a figure in the absence of any reliable
data for its determination would detract from the value of conclusions drawn from the results obtained;
consideration therefore has been limited to the determination of (a) where the only unknown quantity,
in the problem is that denoting the prevalence of influenza. The only record of influenza in the London
population is that of the Registrar General relating to registered deaths, and so far as I am aware no casemortality
figures for the disease relating to any large population are available. It was felt, however,
that some indication of the prevalence of the disease in the general population of London might be
afforded by an examination of the staff returns of illness furnished by the various departments of the
London County Council to the Establishment Committee. These returns relate to some 3,000 officials
on the staff of the London County Council and the influenza case curve which has been constructed from
these records is therefore based upon a population which is of a sufficient size for the purpose in view.
It cannot be claimed that the population in question is a random sample of the London population
inasmuch as it differs materially in age and sex constitution and exhibits more homogeneity with regard
to "social condition" than the London population as a whole. The fit of the "case curve" based on
these figures with the mortality curve for London based on the return of the Registrar General is. so
remarkably close, however, that it appears questionable whether anything would be gained by attempting
to correct for the selective nature of the sample population and whether a random sample of the same
size would have given any more accurate result. Moreover, an examination of the age distribution of
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