London's Pulse: Medical Officer of Health reports 1848-1972

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Hints from the Health Department. Leaflet from the archive of the Society of Medical Officers of Health. Credit: Wellcome Collection, London

Brentford and Chiswick 1956

[Report of the Medical Officer of Health for Brentford and Chiswick]

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Table: SamplingIncreased attention was paid to ice cream sampling in 1956 and during the year 110 samples were taken for bacteriological examination as compared with 46 in 1955. The results of these are as under: -

Sampling

Increased attention was paid to ice cream sampling in 1956 and during the year 110 samples were taken for bacteriological examination as compared with 46 in 1955. The results of these are as under: -

GradeIce CreamCream Lollies
Satis factoryDoubtfulUnsatisfactorySatisfactoryDoubtfulUnsatisfactoryOther SampIes taken
I11--1--Fruit Juices (2)
II45--12--Milk Powder
III-10--2-Fat Powder
IV--12--7Syrups (2)
Not Graded---4--6
Totals56101217276 *

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* Satisfactory result in all cases
It will be observed that the number of samples in Grade I (10%) is considerably
lower than in previous years. This has been brought about by the different
method of grading instituted by the King Edward Memorial Hospital Public Health
Laboratory who substituted an accurate plate count and test for faecal coli for
the methylene blue test, and not as a result of a lowering of the standard of
purity.
An extract from a letter from the King Edward Memorial Hospital Public
Health Laboratory, states that "Since the whole purpose of testing ice cream
is to discover the amount and nature of contamination taking place, we were
obliged to substitute an accurate plate count and a test for faecal coli for the
much easier methylene blue test. Following the precedent usual in food testing
of making the standard the quality reached by known reliable manufacturers, we
set up the following provisional grades*
Grade Count Faecal Coli
I Below 500 0
II 500 - 20, 000 0
III 20,000 - 100,000 0
IV over 100,000 or present
The unsatisfactory samples came from three firms and repeated sampling was
carried out until the results were improved.
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