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examinations—than in small firms." This is not what one would have expected and it would be
most interesting to know whether the employees of the 10 per cent. of such firms who responded are
typical of workers in small firms generally.
Food Poisoning.
Of eighteen cases of food poisoning notified during the year, seven were associated with five
outbreaks involving more than one member of the family and two with minor outbreaks involving
more than one person not of the same family. In three of the family outbreaks pathogenic organisms
were discovered in the patients' faeces, namely Salmonella typhi-murium, Salmonella untyped and
B. Morgan No. 1. In the other two outbreaks no probable agent was discovered. Of the nine single
cases notified, the organism presumed to have caused the illness was discovered in seven, namely
Salmonella typhi-murium (4 cases), Salmonella type "C" (1 case), Salmonella untyped (1 case) and
B. Morgan No. 1 (1 case). Although from time to time several different kinds of food came under
suspicion, it was not possible to establish that any of them were definitely responsible for causing
the illnesses.
Outbreak of Food Poisoning at two schools.
As the result of a telephone call to the office by a general practitioner on Saturday, 20th September,
it was discovered that an outbreak of food poisoning had occurred at two schools in the Borough
on or about the 18th September. Both the school dining rooms concerned were supplied with meals
from the same kitchen. In all, 62 pupils, staff and food handlers out of a total of approximately 230
diners were reported to have had symptoms and, of these, 29 were found to have salmonella organisms
in their stools. Of the 24 specimens typed, 17 were reported to be of the Newport group, 6 probably
Newport and 1 typhi-murium. The cases were spread over 17 different local authorities and none
of the notified cases lived in St. Marylebone.
The symptoms in most cases consisted of severe headache, abdominal pain, diarrhoea, vomiting,
and a temperature of about 103 degrees, accompanied in one or two cases by dizziness. Only a few
of the attacks were severe though in some patients the excretion of organisms persisted for some
weeks after treatment had been completed and they had become symptomless. In view of the length
of time these cases were being kept from school and also taking into consideration that those involved
were all older children, it was decided on 21st October after consultation with the School Medical
Officer that they should be allowed to return to school, provided the Medical Officer of Health concerned
was satisfied that the home conditions were satisfactory and the child understood the principles of
elementary hygiene.
From information received it appeared that the onset in three cases, all positive for salmonella
infection, was between 10 a.m. and 12 noon on 18th September. The organism in one of these was
typed as Newport. A further 10 cases occurred before 6 p.m. on the same day. Of these, 8 were positive
for salmonella infection and of 6 which were typed 4 proved to be Newport and 2 "probably"
Newport. The remainder of the cases occurred in diminishing numbers throughout the evening of
the 18th and the following day.
This clearly demonstrated that infection in at least some of the cases must have occurred before
the midday meal on Thursday, 18th September, which was originally suspected as the possible source
of infection. Attention was thus directed to the midday meal served on the Wednesday, 17th
September, which consisted, among other things, of cold meat cut from the remainder of a joint of
beef used for the previous day's meal and from a joint of pork also cooked on the 16th. Unfortunately,
in accordance with her instructions, the supervisor had destroyed samples of the Wednesday meal
after 48 hours. Examination of specimens of the meal eaten on 18th September revealed the presence
of no pathogenic organisms.
It was noted during the investigations that the menus recorded had not been strictly adhered to.
Meat cooked on Tuesday, 16th September had been used not only on the 17th but also on the 18th,
both as an ingredient of shepherd's pie and as cold meat. Thus the Thursday meal was confirmed as
a potential source of infection and evidence of this was provided by the occurrence of some cases
more than 48 hours after the Wednesday meal.
Swabs were taken from the wash-up sink in kitchen, w.c. pan used by the kitchen staff, rim of
drinking water tap, door handle of w.c., w.c. chain and seat, and from the vegetable preparation sink,
but no pathogenic organisms were isolated. The kitchen where the school meals were prepared was
found to be of a good standard of cleanliness.