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Food Poisoning. There were two outbreaks of food poisoning
in canteens which were the subject of special detailed reports
during the year. The first occurred in June and the second
in December.
In the June outbreak there were 352 cases out of 1,540
exposed. The clinical picture was that of an attack of diarrhoea
coming on nine to ten hours after consuming the mid-day meal,
with absence of vomiting or collapse, the severity of the
diarrhoea varying from one or two stools to five or six and in
one or two cases more or less continuous diarrhoea throughout
the night. This outbreak presented two particular features
which are, perhaps, worthy of record. The suspected article of
food was minced beef which was made up into a galantine. The
interesting point, however, was that it so happened that 190 lbs.
of minced beef was delivered to the canteen and 20 lbs. of it not
required was returned to the butcher. It was possible then to
some extent to compare the fate of the 20 lbs. sent back, which
was retailed to the public and prepared by domestic methods.
There were no casea of food poisoning as far as we could discover
caused by the domestic preparation of the same minced
beef. The other interesting find was that the organism
incriminated was CI. Welchii.
The other outbreak, which occurred in December, produced
171 cases out of a total of 972 exposed. The clinical picture was
of a mild diarrhoea with abdominal pain coming on 8-16 hours
after consuming the meal, with absence of vomiting or collapse.
The suspected meal was stewed steak and gravy and as in the
preparation of the gravy flour was added it would have been
gratifying to have been able to demonstrate an inoculation of
the gravy with soil organisms in the flour, e.g., Welchii, as it
is at leact conceivable when the manufacture and origin of flour
is considered that this is a possibility. However, the laboratory
were only able to grow a few ccliform organisms on blood agar
from the specimens of flour sent. Faecal swalxs grew
staphylococcus in three of the cases.
In both these outbreaks we have the familiar two-stage
preparation of the meal as the precipitating factor.
There were seven other cares occurring as isolated cases or
in family groups. In two of them which occurred singly and
separately Salmonella Typhi Murium was isolated from the
faeces. In one of these cases, a man of 43, there was a history
of duck eggs having been consumed at 5.30 a.m. on the day of
onset. Onset occurred at midnight with vomiting and
abdominal pains. He was admitted to hospital and an
appendicectomy performed, and subsequent bacteriological
examination confirmed the presence of Salmonella Typhi
Murium. The origin of the ducks eggs was traced back through
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