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47
OUTBREAK OF FOOD POISONING
An outbreak of illness which occurred amongst the members of the staff of a
large City trading concern and in which certain indications seemed to point to food
poisoning was investigated in January and February last
Suspicion attached to veal which had been served in the firm's dining room
and of which each of the persons suffering had eaten The remaining portions of
the veal were examined but no fault could be found with it
The veal was purchased on the 20th January and on the 24th the shoulders
and legs were served as roast veal with bacon gravy made from stock and stuffing
comprised of herbs and breadcrumbs Vegetables were also served as were also
fruit salad (made from tinned fruits) suet roll with golden syrup and plum and
apple tart
On the following day what was left of the cooked veal was served as braised
veal No illness was reported among those who consumed the braised veal
In all fortyfour persons complained of having suffered from diarrhoea and
sickness Many of these persons were interviewed and requested to furnish particulars
on a prescribed form drawn up with the object of eliciting essential information
In the majority of cases it was found that the diarrhœal attack commenced in
the early hours of the morning of the 25th In one instance only was vomiting a
prominent symptom The illnesses were not of a serious character all the patients
with one exception being back at work on the 26th January
Samples of uncooked veal of veal cooked and used at the midday meal on
the 24th of veal cooked and prepared on the 25th and of the bacon used on the
24th were submitted to bacteriological examination A rat and a mouse caught
on the premises were also sent to the bacteriologist Unfortunately none of the
stock from which the gravy was prepared on the 24th could be obtained
Two of the patients attended at the Bacteriological Laboratory at St Bartholomew's
Hospital and blood specimens were obtained One specimen of faeces was
also obtained from the one patient in whom diarrhoea continued for more than one
night
The premises and the arrangements for the preparation of the food were
found quite satisfactory and presented conditions above the average
It was found however that on the 24th January a quantity of stock had been
found to be tainted and although instructions were given for its destruction it was
suggested by some of the staff that some of the material might have been used in
the preparation of the gravy used
Sir Frederick Andrewes' report on the specimens submitted for bacteriological
examination was as follows:—
"The material supplied to me for investigation was as follows:—
"(1) Portions of roast veal believed to have been the cause of the outbreak
" (2) Uncooked bacon which had been used
"(3) Stewed veal which had been eaten without illeffect
"(4) Four pieces of raw veal and one kidney from the carcases furnishing the veal
''In addition I examined the blood of two men and the stool of another—all these having
"been sufferers in the outbreak a week previously—also a rat and a mouse caught on the
"premises
"Cultivations of the various meats were made on lactoselitmusagar plates—nine
"plates in all Lactosenegative colonies were present in all plates in some very numerously
"Fourteen such colonies representing all the types present were subcultured for further
"study Many of them were motile Gram negative bacilli but none proved to be members
"of the Salmonella group and none agglutinated with sera of the known foodpoisoning
"bacilli (Gartner Aertrycke and Paratyphoid B sera) The four lots of meat were fed to
"mice Two mice were fed for three days exclusively on each of the four samples of meat
"The two mice fed on No (1) the cooked veal were found dead on the 4th day; the six mice
fed on the other three samples remained unaffected This observation suggests the correct"ness
of the opinion that it was the cooked veal which was at fault
"Post mortem examination of the mice which died showed an acute diarrhœal condition
"the intestines being full of watery fluid The spleens were scarcely enlarged One mouse
"showed numerous haemorrhages in the lungs and elsewhere This mouse yielded an abun"dant
growth of streptococci from the blood and organs Both mice yielded growth of Gram