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of enteric fever was noted, and here again a similar question arose.† Further inquiry was seen
to be necessary in Southwark with a view to tracing in each instance the remote source from
which local vendors were obtaining their milk, and, with a view to obtaining the same information
as to the Lambeth cases, Dr. Priestley, the medical officer of health of Lambeth, was communicated
with, and he made similar inquiries in his district.
The result of these inquiries was to show that in Lambeth no milk from the source in
question was distributed, in St. George-the-Martyr only a small percentage of those attacked was
supplied from this source, and even in Kensal Town, where the incidence upon persons drinking
milk supplied by the particular company was marked, a considerable percentage of the sufferers
from enteric fever obtained milk from entirely different sources. It became, therefore, in
the course of a very short time clear that, striking as was the incidence of enteric fever in Kensal
Town upon consumers of milk obtained from the particular source, and curious as was the fact that
in distantly remote parts of London, milk supplied by the same company had been in a few
instances partaken of by persons who had developed enteric fever, these circumstances were really
devoid of special significance, having regard to the extensive scale on which the supply in question
was distributed. In St. Pancras the incidence upon consumers of the local vendor's milk was
striking, eight cases of enteric fever, which developed symptoms" between August 24th and
October 1st in a circumscribed area, all obtaining milk from this source. The local vendor's
supply may, however, have been contaminated on his own premises.‡ There was in any case no
reason for regarding the St. Pancras outbreak as possessing more than local significance. From
the particulars to be presently given, it will be seen that milk could be definitely excluded from
consideration as cause of the outbreaks in Southwark and Lambeth, and could almost certainly
be excluded in the case of Kensal Town.
Such time as could be found for the work was meanwhile devoted to house to house
inquiry, with a view to recording any facts that were ascertainable in St. George-the-Martyr, where
inquiry was then prosecuted. Questions of sewerage, drainage and refuse disposal were of course
considered, but no indication of a source of infection was forthcoming under these heads. The
manner of grouping of the dates of attack in time was seen to be suggestive of infection on a
particular day or limited number of days, and this fact, taken in conjunction with facts already
referred to, pointed strongly to infection by some kind of drink or food. The difficulty, so far as
most of the possibilities passed in review were concerned, was felt to be the exceptional age
incidence of the disease.
All attempts to find explanation of the phenomena in some gathering together of persons
attacked proved unavailing; the baths and ice-cream hypotheses, which would have to some extent
met the requirements as to age incidence, failed to comply with other necessary conditions. The
question of shell-fish had from the first been kept in mind, and indeed the extent to which the
streets of the area were strewn with periwinkle shells made it impossible, in the light of recent
discussion concerning shell-fish and enteric fever, to ignore the possibility of infection having
been thus conveyed. But a shell-fish hypothesis proved quite untenable on closer examination.
Oysters, it was found, had not been eaten by persons living in the affected area; only
cooked shell-fish, generally speaking, appeared to be consumed there. But it was soon evident
that even on grouping together the comparatively numerous consumers of periwinkles and the far
less numerous consumers of mussels, cockles and whelks, and indeed, on further adding to these
the persons who occasionally purchased shrimps, there would still remain, outside the group so
constructed, a considerable percentage of the total number of those attacked by enteric fever.
The question of age in relation to shell-fish consumption was never reached, inasmuch as this
article of food did not fulfil the cardinal requirement of having been generally eaten by persons
suffering from the disease.
Many other articles of food and drink were made the subject of inquiry. The mother of
one of the patients, on being asked to state, as far as she was able, what food and drink her boy
was in the habit of consuming, remarked, "The only thing he ever did eat in this house (her son
lived away from, and only visited in, the affected area) besides bread and butter was a bit of
fried fish." This remark prompted more particular inquiry in subsequent cases concerning fried
fish, and it then became speedily apparent that most of those who had been attacked, and who were
questioned on this subject, had consumed this article of food, and, moreover, had obtained it from
a particular shop. Again, on examination of the distribution of affected houses, it was evident
that they were grouped about this shop as a centre, and further, that the intensity of incidence
of house attacks rapidly diminished at increasing distances from the shop. This was not all;
in several instances it was found, in particular families, that it was the fried-fish eaters who were
attacked, to the exclusion of other persons not eating fried fish.
Four principal difficulties stood in the way of seriously considering the hypothesis that
infection had been conveyed by fried fish. In the first place the heat to which the fish was
subjected in the process of frying would be not unlikely to destroy the typhoid bacillus.
Secondly, question arose as to how it was possible for the fish to have been originally infected.
Thirdly, there was the age incidence difficulty, and fourthly, it was of course conceivable, in the
absence of precise knowledge of the customs of persons living in the area in regard to fried-fish
eating, that almost everyone was in the habit of consuming fried fish from the particular
shop, and that no special significance could therefore be attached to the observed fact that
practically all the sufferers from enteric fever had eaten this fish.
† In this district it was ultimately found that of the group of eleven cases which had to be dealt with, only
three were obtaining their milk, at the time when infection presumably occurred, from the company already
referred to.
‡ The first case of enteric fever, in the St. Pannras group of cases, occurred in a woman living on the milk
vendor's premises who had recently returned from Wales, and this case may possibly have been the source of
infection of the others.