The principles and practice of medicine : designed for the use of practitioners and students of medicine / originally written by the late Sir William Osler.

  • William Osler
Date:
1925
Catalogue details

Licence: Public Domain Mark

Credit: The principles and practice of medicine : designed for the use of practitioners and students of medicine / originally written by the late Sir William Osler. Source: Wellcome Collection.

    37/1272 page 3
    mer rise, two secondary maxima in the winter and spring, and these authors suggest that epidemics at these seasons are characteristic of cities whose water- supply is most subject to pollution. In their opinion “the most reasonable explanation of the seasonal variations of typhoid fever is a direct effect of the temperature upon the persistence in nature of the germs which proceed from previous victims of the disease.” Of 1,500 cases at the Johns Hopkins Hospital (upon the study of which this section is based), 840 were in August, September, and October. Sex.—Males and females are equally liable to the disease, but males are much more frequently admitted into hospitals, 2.4 to 1 in our series. Age.—Typhoid fever is a disease of youth and early adult life. The great¬ est susceptibility is between the ages of fifteen and twenty-five. Of the 1,500 cases there were under fifteen years of age, 231; between fifteen and twenty, 253; between twenty and thirty, 680; between thirty and forty, 227; between forty and fifty, 88; between fifty and sixty, 8; above sixty, 11; age not given, 1. Cases in advanced life are not uncommon, but as the course is often atypical the diagnosis may be uncertain and the disease not recognized until autopsy. It is not infrequent in childhood, but infants are rarely attacked. Murchison saw a case at the sixth month. Immunity.—Not all exposed to infection contract the disease. After re¬ covery the immunity is apparently permanent but only against the particular infecting organism; infection with the typhoid bacillus does not protect against paratyphoid infections and vice versa. In 500 of our cases in which special inquiry was made as to a previous attack it was found to have occurred in 2.2 per cent. The interval varied from nine months to thirty years. Usually within a short time after recovery the immune substances disappear from the blood, yet in most cases the immunity lasts for life. An experimental explana¬ tion for this fact has been given in the demonstration that animals which have once reacted to the typhoid infection, react in throwing out immune substances more quickly and in larger amounts when danger again threatens (Cole). Bacillus Typhosus.— (a) General Characters.—It is a rather short, thick, flagellated, motile bacillus, with round ends, about 3pi in length and 0.6p. in breadth. This organism fulfills all the requirements of Koch’s law—it is constantly present, and grows outside the body in a specific manner; the third requirement, the production of the disease experimentally, has been met by its conveyance to chimpanzees. The disease has resulted from the swallowing of cultures with suicidal intent. The bacilli or their toxins inoculated in large quantities into the blood of rabbits are pathogenic, and in some instances ulcerative and necrotic lesions in the intestine may be produced. But similar intestinal lesions may be caused by other bacteria, including Bacillus coli. Cultures are killed within ten minutes by a temperature of 60° C. They may live for eighteen weeks at —5° C., although most die within two weeks, and all within twenty-two weeks (Park). The typhoid bacillus resist's ordi¬ nary drying for months, unless in very thin layers, when it is killed in five to fifteen days. The direct rays of the sun completely destroy them in from four to ten hours’ exposure. Bouillon cultures are destroyed by carbolic acid, 1 to 200, and by corrosive sublimate, 1 to 2,500. (6) Distribution in the Body.—The bacilli are probably in the circulating blood in the early stages of the disease in all cases. During life they may he
    digitised image 1
    digitised image 2
    digitised image 3