View report page

7
The Central Public Health Laboratory isolated a staphylococcus
commonly associated with food poisoning from a sample of the
original artificial cream ; from the remnants of the dried milk used in
its preparation and from several unopened tins of the same brand of
dried milk.
All other investigations, including examination of kitchen staff,
were negative and it was finally established that the cause was infected
dried milk.
On the day of the outbreak no less than 732 meals were prepared
by the Central Kitchen and of those who consumed them, 355 are
known to have had symptoms of poisoning. It is probable that many
others had trivial symptoms which were not reported.
It transpired later that similar outbreaks occurred at Epsom,
Banstead, and in the London area, and the cause was found to be the
same brand of dried milk.
All remaining stocks of this milk held at schools throughout the
county were withdrawn and no further cases occurred.
Outbreak No. 2.
In October there was a small outbreak involving 8 people who
had symptoms very suggestive of the staphylococcus food poisoning
described above.
In this case it was found that the cook had an infected finger and
that she partly cooked the meat on the day before consumption,
re-heating it on the following day. Conclusive bacteriological proof
was not obtained, but it is reasonable to assume that the meat or
gravy was contaminated by the cook's finger on the day when it was
pre-cooked. During the night the organisms were able to multiply and
to produce toxims. These would not necessarily be destroyed by the
warming up process on the following day and would cause symptoms
of food poisoning.
This habit of cooking food on the day before consumption is most
dangerous and is commoner than is generally appreciated. Efficient
storage in refrigerators minimizes this danger but the practice cannot
be too strongly condemned.