Memorandum on typhoid fever.

Date:
1939
Catalogue details

Licence: Public Domain Mark

Credit: Memorandum on typhoid fever. Source: Wellcome Collection.

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    or of those in attendance upon a patient, and infection of food by subsequent handling. Infection by hands should not occur with reasonable precautions. | Water, however, is the most widely consumed of all commodities and the biggest outbreaks of typhoid fever in this country in which the source of infection has been ascertained have been water-borne. In the event of a single person contaminating a water supply many thousands of persons may be at risk. Sporadic cases occurring weeks apart, but re-appearing year by year in a district and giving the appearance of endemicity, may be due to the repeated specific pollution of a water supply and the ‘‘ endemicity ”’ ceases with the discontinuance or purification of the supply. Moreover, even where large populations are concerned, water- borne infection does not always give rise to “‘ explosive ”’ out- breaks. A study of the outbreaks which have occurred in recent years shows that, while gross sanitary defects are becoming less and less responsible for the persistence of typhoid fever, special danger lurks in the modern methods of wholesale and wide distribution of milk and other foodstuffs which often make it very difficult to trace the human originator of the infection. The great majority of milk outbreaks have been due, not to direct infection by a carrier but to the washing or rinsing of milk utensils in specifically polluted water; they were to this extent water-borne, as was the case with outbreaks due to the consumption of shellfish gathered from layings polluted by water containing sewage. . Thus human dejecta, in one form or another, are responsible for the spread of the disease; their ordinary form is domestic sewage. It is important to note that specific organisms of the enteric group may sometimes be recovered from sewage in the absence of avowed clinical cases in the areas from which the sewage is derived. Outbreaks of water-borne typhoid fever are sometimes asso- ciated with early attacks of nausea and vomiting, with or with- out diarrhoea, among the consumers. These attacks occur within a period of 12-72 hours after ingestion of the polluted water and, therefore, about three weeks before the notification of such cases of clinical typhoid fever as may have contracted the specific infection at that time. The attacks may be so transient as not to necessitate medical attention and, in outbreaks of typhoid fever suspected to be water-borne, inquiry into their occurrence should always be made. Commonly the subjects of them do not develop clinical typhoid fever but occasionally they do, becoming ill again at the same time as those who have incubated the disease without previous dis- turbance.