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considerable paratyphoid group of cases was that above referred to; when this last named outbreak
occurred there was some influenza in London but the disease was not nearly so prevalent as was the case,
in 1918.
Reference has been made (p. 2 ) to the facts, that in London (at any rate) the great decline of
typhoid fever in the latter half of the last century was due in the main to improvement of water and food
supplies, and that the continued and accelerated fall of the last 20 years was mainly attributable (the
water being for the most part beyond suspicion) to improvement effected as regards supplies of shellfish
and fish from certain sources. On the other hand, no clear evidence has been adduced during the last
25 years to show that carriers, flies, milk, ice-cream or watercress have spread typhoid fever in London.
There remain to be considered two further possibilities ; first the view, which still finds some favour,
that considerable importance must be attached to direct case to case infection ; and, second, the opinion
now beginning to find expression that preventive inoculation has caused a lowered incidence upon young
men since the war.
In support of the former view appeal is sometimes made to nurse infections and to infections of
laboratory workers. The number of cases notified in nurses has been carefully recorded in London for
many years past. In 1919 there were four, last year there were eight such cases. The whole question
was considered in a paper on " Typhoid Carriers and Contact Infection " (Proc. Roy. Soc. Med. Epidem.
Sect. 1910, p. 128-130), the data relating to the preceding 20 years being analysed. It transpired that
the incidence of typhoid fever upon nurses "does not very much exceed that upon other women of those
ages in London in those years." Moreover, as typhoid fever has especially affected in the past certain
sections of the London population, question arose as to whether nurses had circumstances in common with
the sections of the population which have escaped, or with those more especially attacked. Again, the
likelihood of detection of atypical and obscure cases of typhoid fever in nurses in institutions is, of
course, distinctly greater than in persons outside institutions. Furthermore, the cases in nurses were
found as a rule to present themselves in groups, and in several instances the circumstances were suggestive
of food causation. When nurse infection is thus considered as a mass phenomenon, the ordinary
opinion as to risk run by nurses, in the particular respect in question, does not find confirmation.
Reference was made in the Annual Report for 1912 to the fact that the available data relat ing to laboratory
workers, supposed to have been directly infected with typhoid cultures, stands in very similar case.
It has been pointed out from year to year, in recent annual reports, that any conclusions drawn
from statistics relating to inoculation in the armies engaged in the late war need to be considered in the
light of the corresponding statistics for the civilian communities of the nations concerned. It has,
however, been only too commonly the practice of writers on the subject, in discussing attack rates and
death rates of the armies in the recent war, to contrast them with attack rates and death rates in previous
wars. Such comparisons are of course beside the mark. For, while it is quite true that the recent military
rates are only one tenth or one twentieth of those in previous wars, the same statement holds good
as a ride with respect to the corresponding civilian rates also.
In last year's report, page 12, reference was made to the American and German military experiences,
which indicated that the case for the general adoption of inoculation is by no means clearly made
out. But, perhaps, an even more important point is the teaching of the figures for the years immediately
succeeding the war. If anything more than a transient and partial protection is claimed, then as
demobilisation was effected it should have been clearly evident that there was a very material reduction
in the male rates as compared with the female rates among civilians, in view of the fact that the demobilised
men had as a rule been inoculated. Such a claim has in fact been recently made (see Journal of the
American Medical Association, 27th November, 1920, p, 1501), it being urged that in 1919 there is evidence
to show that in the experience of a particular metropolitan life insurance company the male rate had
declined 64 per cent, as compared with a corresponding decline of only 47 per cent, in the female rate,
when comparison was made between 1919 and the years 1911-16. Appeal is also made to the low rate
in the male white population of the United States between 20 and 35 years of age, which is given as
8 0, and is only slightly in excess of the corresponding female rate (7"9 per 100,000). There are possible
fallacies here ; we are assured that the population figures must not be too implicitly relied on, and in the
case of the insurance company the figures under review cannot be very large.
Since this point was raised in America, a study of the available military statistics for this and other
countries has appeared in the International Journal of Public Health, (Vol. 2 No. 2, March-April, 1921).
An opinion on the whole favourable to the influence of inoculation is given in this review, but there is not
anything approaching unanimity of testimony on this head, and there is apparent as before the tendency
to compare present day case rates and death rates with those of twenty or more years ago. Thus, the
writers referred to in this review argue from the data of the Great War, back to those of the Boer War,
or, in the case of the American Army figures back to the figures of the Spanish American War.
At the time of sending the present report to press, No. 3 of the Journal above referred to, containing
a review of the " Anti-typhoid Inoculation of Civil Populations," has just come to hand.
References are given to 60 papers dealing with the subject; again opinion is divided but by some
writers the wholesale inoculation of civilian populations is advocated. There is apparent, however, on
the part of these writers a disposition to infer that compulsory inoculation during an epidemic, followed
by decline, or cessation of the prevalence, proves the case for inoculation. (See, for example, the Kansas
Hospital case on p. 285, and the Paris Boarding School experience, p. 286). But, in the same way the
inauguration of mere bacteriological examinations pn Drigalski-Conradi lines, without any inoculation,
in a London institution sbme years ago, was immediately followed by cessation of a severe typhoid
prevalence. As the bacteriologist entered the door of the institution the typhoid bacillus, metaphorically
speaking abandoned the unequal contest. In contrast with these experiences were those of the milk
61004 E
Causation of
typhoid fever
in London
Anti-typhoid
inoculation.