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4. Risk from Personal contact with a Case or Carrier.
During the ten years under review, multiple cases of typhoid fever occurred in the same
household, e.g. in 1962 this happened on three occasions, illustrating the danger of close personal
contact with infected persons. In addition, one of those instances again illustrates the notoriously
long duration of the carrier condition during which the risk of infection exists. In a household
with one of the 1962 cases, another two persons had been infected, one in 1957 and the other in
1947, by the same chronic carrier.
The risk of personal contact in mental hospitals with known chronic carriers is well known.
This again occurred in 1962 when some cases were contracted in this way during that year.
Another outstanding occurrence of infection by personal contact is the mother who had typhoid
fever in 1907 and infected three of her children at that time. The same woman as a grandmother
attending a christening party of her grandchildren 54 years later in 1961, succeeded in infecting
five small children, four of them her grandchildren, although she had not prepared any of the food
for the party.
In the same year, 1961 there were six other family incidents. In the previous year in Portsmouth
an outbreak of seven cases and one excreter were caused by a father and two small sons
who were incubating the disease, visiting and infecting the grandparents as well as three lodgers
who stayed with them. This gives an illustration of personal case-spread though the primary
source of the outbreak was not traced.
One wonders whether a reconsideration of the histories of outbreaks where the cause was not
found at the time, would reveal any possibility of canned food as the missed source. It is most
intriguing to see how Dr. E.S. Anderson6 re-examined the evidence of the Oswestry outbreak
which was thought at the time to have been caused by milk-borne infection7. This source was not
substantiated, as most of the cases occurred amongst nursing and domestic staff of a hospital
whereas consumers from the same milk supply outside the hospital were not involved. Phage
Typing also confirmed that the milk was not the vehicle of infection. Recent re-typing of the
organisms has established that it was Phage Type 34, the same as that responsible for the Aberdeen
outbreak. In addition, corned beef was an item in the meals consumed by the domestic and
nursing staffs about the relevant dates of infection. This may dispose of milk as a recent vehicle
for the conveyance of typhoid, but it is to be noted that milk has recently been responsible for
conveying food poisoning, so it may be convenient at this point to consider-
5. Risk of infection from Typhoid compared to other Salmonella Food-borne Organisms
For this purpose the year 1963 is taken as the most recent for which figures are available.
In 1963 there were 247 corrected notifications of typhoid fever. This is almost twice the annual
average incidence for the preceding ten years. With the number of cases in Aberdeen this incidence
will be almost doubled again in 1964. In 1963 there were 342 corrected notifications of
para-typhoid fever whereas there were some 13,000 cases of food poisoning reported including
cases where cause was not discovered (about 10,000 notified cases). Closer liaison is necessary
between notifying medical practitioners, medical officers of health, the Ministry of Health, and the
Public Health Laboratories, to secure more accurate statistics. It would appear that the figures
given in the annual report of the chief medical officer of the Ministry of Health for 1963 are not
comparable to those given in the Monthly Bulletin of the Ministry of Health and the Public Health
Laboratory Service for the same year. There were 15 deaths associated with food poisoning according
to the Ministry of Health report; 27 deaths are recorded by the Laboratory Service. Three
different sets of figures of incidence for Salm typhi-murium are to be found, one, in the Annual
Report of the Chief Medical Officer of the Ministry of Health for 1963s, and two others in the
Monthly Bulletins of the Ministry of Health and the Public Health Laboratory Service for 19649,10.
In particular the risk of contracting Clostridium Welchii food poisoning appears to be on the increase,
the notifications have almost trebled in a year, being 3,377, and of these four died, three
of them following a meal which included boiled ham11. In nearly all the C. welchii outbreaks the
pre-cooking of meat, which was subsequently eaten cold or re-heated inadequately before being
consumed was the underlying factor. This seems to have been a common practice in hospitals and
schools where two thirds of the outbreaks occurred. This happens in spite of the condemnation of
such practice and repeated warnings regarding the dangers involved.
6. Risk of Infection by Enteric Fever and Food Poisoning associated with different foods.
Apart from the Zermatt outbreak of typhoid fever in 1963 (68 cases) there were three major
outbreaks in that year each associated with corned beef sliced from 6 lb cans, one each at Harlow
(26 cases), Bedford (23 cases) and South Shields (27 cases). A visitor to this country from Holland
contracted infection in this country from infected oysters, which reminds us that there is still
the risk of contracting typhoid fever from shellfish. The Dutch case was one of a series of twelve
cases occurring during the autumn of 1958. These were all presumed to have been caused by the
ingestion of infected oysters derived from one group of layings. Shellfish from a foreshore contained
Vi Phage Type E.l strain Salm. typhi, as did two cases of typhoid who had partaken of
cockles gathered on the same foreshore in 1956 near a sewage outworks. So shellfish are still a
risk and in particular those not subject to treatment las required by Orders made under the Public
Health (Shellfish) Regulations, 1934. Four outbreaks of paratyphoid fever were associated with
the use of Chinese frozen egg in bakeries.
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