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very notably in question. In some instances, for example, in an outbreak in 1910
(Annual Report, Medical Officer of Health, 1910, Chap. XXXII., p. 105, Footnote),
the cases among nurses were almost unquestionably of food origin. In other instances
in 1893, 1899 and 1900, outbreaks affecting staff in Metropolitan Asylums Board
hospitals coincided in time with outbreaks (probably of food origin) in the surrounding
neighbourhood. Again, cases affecting nurses tend to occur in groups. On the
other hand it has been observed that the notifications relating to Metropolitan
Asylums Board nurses show a tendency in the later series of years to be delayed
in point of time as compared with other notifications, and this might be held to
suggest case to case infection. The number of Metropolitan Asylums Board nurses
involved in these later years is not, however, sufficiently large to permit of stress
being laid on this point; it may, moreover, be the fact that in the case of nurses
notification is held over for a week or two until the diagnosis has been finally confirmed.
Private establishments and other institutions.—As regards these some 54 cases,
occurring in a City establishment in 1899 where the employees were catered for
on the premises, may well have been due to food. A like origin is possible in the
case of 11 cases developed in 1914 in a shelter for Polish refugees; and also in 70
or 80 cases occurring, in the last fortnight of 1913 and the first six or eight weeks
of 1914, to which special reference is made in the Annual Report for 1914.
The cases of typhoid in institutions considered as a whole show so marked a
tendency to occur in groups, as to make a food origin highly probable. Judged
by the behaviour of typhoid fever in London, elsewhere than in institutions, fish
necessarily falls under grave suspicion; though it should be noted that the small
institution outbreaks often occur at times of the year other than the 37th-48th
weeks, when typhoid prevalences on a large scale, presumably of fish origin, have
been apt to prevail. It must be remembered, however, that proof that fish has
been at fault has only been pressed home in the past in considerable prevalences
in which, moreover, immature and imperfectly cleansed fish have been consumed.
It is highfy probable that such instances may be practically limited to a special
season of the year; but if it be granted that this is the case, then it will be readily
agreed that small groups, or actual sporadic cases, may result at other times from
distribution of material possessed of a less pronounced capacity for causing disease.
Report on Bacteriological Work.
The work done in the bacteriological laboratory during 1922 comprised the
examination of nearly 8,500 specimens, including chiefly cultures from throat and
nose, in connection with diphtheria investigations in the schools and suspected
ringworm hairs from school children, also material sent for diagnosis from various
institutions or obtained in the course of consultation visits to parents' homes by
Dr. J. A. H. Brincker and Dr. J. G. Forbes. The bacteriological analysis of this
large amount of material involved the use of over 10,000 tubes and plates of solid
and liquid media prepared and sterilised by the two laboratory assistants. The
media employed included serum, lactose litmus agar, special media prepared according
to McConkey's, Gordon's and Hiss's formulae, also ordinary agar and gelatine,
broth. peptone and various suger nutrient preparations for differential diagnosis.
Details of
laboratory
examinations.
(I.) Diphtheria Investigations.—5,401 cultures from throat and nose (school
children and Council's staff), of which 471 or 8.7 per cent. showed the presence of
the diphtheria bacillus, 377 or 7 per cent. suspicious organisms and 4,553, or 84.3
per cent. proved negative. The diphtheria bacillus was isolated in pure culture for
the application of animal virulence tests by the Wellcome Research Laboratories in
290 (or 62 per cent.) of the total diphtheria carriers. In 37 cultures from discharging
ears the diphtheria bacillus was isolated and identified in 2 only, the rest showing
diphtheroid and other organisms.
(II.) Ringworm.—2,845 hair specimens were examined. 1,372 proved negative
and 4 suspicious. In 1,459 ringworm fungus was found ; 86 per cent. being the small