View report page

37
High School for Girls
At the beginning of October a parent reported that she suspected
her daughter to be suffering from food poisoning.
Immediate investigations were made and the diagnosis was later the
same morning confirmed by the Family Doctor. Enquiries were made
at the school which ultimately revealed that 52 members of the staff
and pupils were affected over the weekend, but all were back at
school except for the first case reported.
All those affected had partaken of the school meal cooked at
the school kitchen on the previous Friday and eaten at the first
sitting. None who had taken the meal at the second sitting and
which had been cooked at the central kitchen was affected.
The meal at the first sitting consisted of cold roast pork and
salad, followed by a chocolate pudding and sauce. The Deputy
Chief Public Health Inspector who investigated the outbreak reported
as follows:—
"The roast pork consisting of four legs boned and rolled by
the butcher were delivered to the canteen on Thursday morning,
27th September. They were cooked in a moderate oven for
hours approximately and then placed in the food store to cool.
This room faces North and is reasonably cool. After several hours
cooling the pork was placed in the refrigerator when the canteen
closed for the day about 4 p.m. It was taken out of the refrigerator
for slicing at 11 a.m. on Friday and was eaten at 12.15 p.m. The
chocolate sauce was made of fresh milk, dried milk powder, cornflour,
sugar and cocoa. This was prepared from 10.30 a.m. onwards
and according to the manageress, was kept at a temperature at or
near boiling point until it was actually served at 12.30 p.m.
"The incubation period, symptoms and duration of illness point
to an infection with C1. welchii. If that is the case then the cold
roast pork is the most likely vehicle of infection. As 52 of the
233 persons who partook of this food were infected and the meat
was cut from four separate joints, it may be that only one joint of
meat was responsible. The technique of cooking does not appear
to be at fault and it would seem possible that one of the joints
was infected during the boning and rolling process and that the
heat during cooking did not penetrate to the centre of what was
known to be a thick joint sufficiently to kill the organism, with
the result that the C1. welchii multiplied during the cooling process.
"This outbreak would never have been discovered but for
the persistence of Mrs. S. It is interesting to note that a food
hygiene lecture was given to a Women's Organisation at Mrs. S.'s
house two years ago, and it would appear that Health Education
does sometimes prove effective."