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35
The distribution of cases of enteric fever throughout the year was characterised by an increase
of prevalence in the 49th, 50th and 51st weeks. Previous experience of the distribution of cases of
this disease in London during the period 1890-3 shows that this behaviour of the disease in 1894 was
exceptional, and further inquiry shows that the increase was not due to any special local prevalence, but
was manifested over a large area of the county. I have therefore made inquiry as to the water supply
of the houses invaded in London with the result that it was found that this exceptional increase was
observable in the population supplied by all the London water companies except the East London and
the Kent companies. Study of the results of chemical examination of the waters supplied by the
London water companies, and which are published by these companies, shows an intimate relation
between the condition of the waters as supplied and the condition as to flood of the rivers from which
these waters are derived. Certain notable floods in November materially altered the condition of the
waters supplied, at a time when there is reason to suppose that some new factor in the causation
of enteric fever in London must have come into operation.
Inquiry as to the behaviour of enteric fever in populations in the vicinity of the county
gives indication of some difference of behaviour of this disease in the population supplied by water
from the Thames and Lea, and in the population otherwise supplied, the population supplied from
these rivers, experiencing an increase of disease in the 49th, 50th and 51st week, corresponding with
that experienced in London.
The hypothesis of water-borne contagion appears better able than any other to afford explanation
of the increase of disease in the weeks in question.
In a memorandum which was presented to a committee of the Council, and which is appended
to this report, the subject is considered in more detail. (See Appendix II.)
The only considerable local outbreak of enteric fever in 1894 is discussed in the report of the
medical officer of health of Lambeth. The circumstances of this outbreak, briefly told, are as follows.
Between the 10th March and 21st April 49 persons living in Lambeth and in adjoining districts were
attacked with enteric fever, 45 of whom received their milk from the same dairy. The dairy received
its milk from three sources—(a) an amount averaging from 20 to 25 churns a day from a large
proprietary farm; (b) a less amount from a firm of dealers at Salisbury, who supplied milk from
several stations on the South Western line, and from one station on the London, Chatham and Dover
Railway ; (c) some three or four churns a day from certain Brixton sheds.
The milk from (a), the proprietary farm, was distributed in an area which was practically free
from disease, the milk from (c), the Brixton sheds, was supplied to customers as nursery milk, the
addresses of families thus supplied being recorded, and these persons also remained immune. As to
the milk supplied by the Salisbury dealer, Dr. Verdon says, " On inquiry it was ascertained that many
dairies in Lambeth, in whose area of distribution no typhoid was found, had also obtained consignments
from this dealer, some from one station and some from another. In fact, milk from all stations was in
daily consumption in Lambeth." No dairy, however, other than the dairy in question, "had among its
customers a succession of typhoid cases." On this evidence, Dr. Verdon says, "it is unreasonable to
suppose that milk from this source, the Salisbury dealers, was per se infective."
In discussing the cause of the outbreak, Dr. Verdon states that in the Lambeth dairy was a
tank, the water of which was used for washing carts and trucks, and which contained a quantity of
filth, no doubt thus introduced. His assumption was that milk was rendered infective in the dairy.
The chief point of interest in the report is that the supply of milk from the proprietary farm
and the Salisbury dealers was stopped from April 3rd to April 7th, and that " within 10 days of interference
taking place with the course of business at the dairy, a period admissible for cases already
infected to declare themselves, the epidemic completely and totally collapsed, leaving only two belated
cases to follow 10 days afterwards."
In the reports of the medical officers of health instances are given of infection communicated
from person to person, the attendant circumstances often being such that the scrupulous cleanliness
requisite in the care of the sick was wanting. Thus, in Kensington, the medical officer of health reports
that four cases occurred in one overcrowded house, three of them being due to contact with the sick. The
medical officer of health of Hackney shows with much exactness the relations existing between the several
cases in a series which extended from September, 1893, into May, 1894, and which occurred in several
houses in two streets, infection evidently being communicated from one person to another. Again, of
six persons attacked by enteric fever in St. Olave four were nurses.
In several of the reports the possibility that oysters might be concerned in the causation of the
disease is discussed. Thus, references to this subject are found in the reports relating to Paddington,
Marylebone, Hampstead, Strand, Wandsworth (Claphamand Putney) and Deptford. With this subject
the possibility of infection being conveyed by watercress is also considered. The medical officer of
health of Marylebone analyses the circumstances of 64 cases of enteric fever in that district, and states
that ten ate of both oysters and watercress, eight ate watercress but no oysters, and four ate oysters
alone. "Some of the cases," he says, "may therefore have been through oysters or watercress, but the
numbers consuming one or both are not sufficiently striking to base general conclusions on." The
medical officer of health of Clapham says," In some of the cases reported here it was found that the
patients had eaten oysters, as indeed was most likely, but I did not attach much importance to the few
instances discovered." His colleague, discussing the cases which occurred in the sub-district of Putney
writes, "This disease was unusually prevalent over London during the last quarter of the year, affecting
to a great extent the upper classes of society. It has, I think, been undoubtedly shown that many
cases were the result of eating oysters. Of the three fatal cases which occurred in this sub-district one
of them at least was, in my opinion, due to this cause. It was the case of a temperate man and careful
living man. No sanitary defects were found in the house. He was not a water drinker. About
ten days before the symptoms appeared, on going up to market in the morning he partook freely of
oysters, and by a process of exclusion I am driven to conclude that this was the only probable source of