Typhoid Outbreak in Larkhall 1905

from the Annual Report of the County & District Medical Officer

Special Report on Milk Epidemic

In Dalserf parish 124 cases occurred. This epidemic was due to an infected milk supply, and the history of the outbreak is narrated in the following special report:-

Seven years ago (October, 1898) the inhabitants of Larkhall suffered from an epidemic of typhoid fever, caused by an infected milk supply. The disease was widely distributed, and in the following year there was a considerable prevalence; but since then the incidence has been very slight, and reached a minimum last year, when only four cases were notified, and not a death from this disease registered. See Table I. 

Table 1 - Cases notified and death registered from typhoid fever in Larkhall during the eight years 1898-1905


1898
1899
1900
19011902
1903
1904
1905
 Cases
 127 42 18 218
 16 4 124
 Deaths 14 3 2 3 1 2 .. 6

During the current year the disease was almost entirely absent from Larkhall and neighbourhood until the present epidemic.

In the month of June one case (a child aged three years) occurred at Meadowhill Rows. After fully a fortnight's illness the patient was notified and removed to hospital. About the 12th August a lad of 18 years sickened at Hareleeshill Road, was notified on the 24th August, and removed to hospital. No other cases were brought under our notice until the 26th September, when the notifications increased daily, so that by the 14th October 90 cases were reported The following Table II. gives the statistics for the whole year:-


 

Jan

Feb

Mar

Apr 

May 

Jun 

Jul

Aug 

Sep 

Oct

Nov

Dec

Cases

 ..

 ..

 ..

 ..

 ..

1

 ..

 1

 14

 93

 10

 5

Deaths

 ..

 ..

 ..

 ..

 ..

 ..

 ..

 ..

 ..

 2

 4

 ..

Proceeding to consider the cause of this epidemic and the preventive measures adopted, it will be remembered (1) that typhoid fever has a long incubation period - frequently 12 to 14 days; (2) that, as the symptoms are extremely variable and often indefinite, the disease is difficult to diagnose before the eighth day of illness, and sometimes is so mild that medical aid is not summoned ; and (3) that while the disease is commonly transmitted from the sick to the healthy, as in other infectious diseases, it only occurs in widespread epidemics when the infective germs find entrance to a public water, milk, or other food supply.

Cause of the epidemic & preventative measures adopted
If we now classify the cases according to date of onset of illness (this can only be done approximately), we can study the progress of the epidemic or distribution as regards time.

See Table III. , Table IV., Table V. and Table VI

We observe that the epidemic prevalence began in the week ending 16th September, and continued until the end of the month. During the latter half of September 83 persons were attacked, and during the first fortnight of October only 15 persons, of which 13 were probably secondary cases.

Cases have occurred in almost every quarter of the town of Larkhall, and the total number of households affected was 64, with 89 persons attacked. Eight different localities, about 2 miles to the east and south of Larkhall, have also suffered, and the total number of households affected was 19, with 33 persons attacked.

The heaviest incidence occurred between the 20th and 29th September, when 65 persons were attacked. Forty-three of this number were in Larkhall, and 22 in the neighbouring districts.

The distribution within the town, and the incidence on the places outside of Larkhall, is of special interest in connecting the cases with the milk supply, and will be seen by reference to the map, where the course taken by the milk cart is indicated by a red line and the houses invaded by a red circle. The map [click here- large file] shows that cases have occurred in almost every street along the route taken by the cart.

All these facts indicate that there has been some widely operating source of infection, and not such as occurs in personal or house-to-house infection.

The water supply is from the upland sources of the Middle Ward Water District which is distributed to many towns and villages where no typhoid prevails, so need not be further considered.

The milk supplies are very numerous, there being about 23 registered dairymen selling milk in Larkhall and neighbourhood. Only a few of these dairymen are cow-keepers, so most of the retailers obtain their milk supplies from dairy farms at a distance. Many households obtain milk from two or more milk-sellers.

The first notifications were received on 26th September, and at the very commencement of the outbreak one of the milk supplies came under suspicion, as the first cases notified obtained the whole or part of their milk supply from one dairy. The Assistant Medical Officer of Health (Dr. Hislop) at once visited the dairy premises, but obtained no evidence of any recent illness among those engaged in the dairy business. Next day he visited the two dairy farms supplying the milk, and there also found no evidence of recent illness among the inmates or those engaged in the dairy business. There was thus, on the one hand, as the result of enquiries made at the households affected with typhoid, a considerable amount of evidence that this milk supply was a source of infection; while, on the other hand, as the result of enquiries made at the places of milk production and distribution, a lack of evidence as to how the milk could have been infected.

With considerable anxiety the matter was kept under consideration and discussed with the staff day by day until the 3rd October, when there was a large increase in the number of notifications, which, after being inquired into, showed conclusively that the milk supply had disseminated the infection. We had now to consider - Was the milk still infective? The dairyman was visited and informed of what had happened. He was asked not to sell milk meanwhile, and have all those engaged in the dairy business examined medically and their blood tested for a typhoid reaction. He refused to submit to this test, and next day called at the office feeling evidently very much aggrieved at the action taken. That afternoon, however, he indicated, through his law agents, his willingness to have the test applied. The dairy farmers were also advised to accede to our requests. On the 5th October the tests at the dairy and at one farm were made with negative results. A note was given to that effect, and the business resumed. The examination of the second dairy was not completed until the 8th October. Although a definite source of infection for the milk supply has so far not been discovered, we are not without good evidence that there was communication between a house in which one of the first cases occurred and the dairy premises, and there must have been at some period, probably early in the month, accidental and temporary contamination of the milk supply. This is borne out by the further progress of the epidemic, which practically ceased at the end of September, thus pointing to some transient infection. In fact, the milk as a source of infection had ceased to operate before even the first cases were notified.

The evidence of milk infection in this epidemic is at present even stronger than in that of 1898, when the source of infection was quite apparent. For example, the number of households affected in 1898 was 66, and of these only 46 obtained milk from the infected dairy. In the present epidemic the number of households affected is 83, and of these 67 obtained milk either wholly or partly from the infective supply.

See diagram

The area, of distribution of the disease bears a close relation to the distribution of the milk supply. If reference be made to Table VI. it will be seen that there are 3,567 houses in Larkhall and other parts of Dalserf Parish, and of these 83 have been affected with enteric fever, giving a proportion of 1 household affected to every 43 houses.

On the other hand, it was found that milk was distributed to about 200 households, and 83 of these had been attacked, so that the proportion of households affected to households receiving milk from this dairy is about 1 in 2 1/2.

The administrative measures adopted were the prompt isolation of each case, followed by disinfection of the premises and bedding.

All patients removed were admitted to the Middle Ward Hospital, Motherwell, where the staff successfully met the requirements.

Inquiry was also made into all cases of sickness suggestive of mild forms of the disease, and, to assist the recognition of doubtful forms, many blood specimens were taken for examination in the bacteriological laboratory.

For instance, it was not an uncommon experience to find patients attributing their illness to influenza, a sick headache, or deranged stomach. In several instances the patients were even at work and had never been confined to bed, although actually suffering from the disease, and were only discovered by careful inquiry at the houses visited into what appeared to the inmates to be a slight indisposition. In many instances a house-to-house visitation was made and the necessity of medical attendance urged in all cases of lesser ailments.

Special attention was given to sanitary arrangements. Open channels were cleaned and ashpits and privies emptied and disinfected wherever it was considered necessary.