Infection, immunity and serum therapy : in relation to the infectious diseases which attack man; with considerations of the allied subjects of agglutination, precipitation, hemolysis, etc. / by H. T. Ricketts.

  • Ricketts, Howard Taylor, 1871-1910.
Date:
1906
Catalogue details

Licence: Public Domain Mark

Credit: Infection, immunity and serum therapy : in relation to the infectious diseases which attack man; with considerations of the allied subjects of agglutination, precipitation, hemolysis, etc. / by H. T. Ricketts. Source: Wellcome Collection.

Provider: This material has been provided by the Harvey Cushing/John Hay Whitney Medical Library at Yale University, through the Medical Heritage Library. The original may be consulted at the Harvey Cushing/John Hay Whitney Medical Library at Yale University.

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    Infectious Disease. Infestation and Infec- tion. Contagiousness and Infectious- ness. An infectious disease is one which is caused by living organisms which in some way have been introduced into the tissues of the body. Accord- ingly the word has reference to the nature of the cause of the disease. It is from the Latin inficire, meaning to place in or into. Where living organisms exist on a body sur- face, as the skin or intestinal tract, the surface is said to be infested; the skin, for example, is in- fested with pediculi. One may also say that the intestinal tract is infested with tape worms, but here the distinction between infestation and in- fection is not to be drawn so sharply; surely when the larva? penetrate the intestinal wall and reach the circulation or distant organs we must speak of infection. But even the adult tenia as it ex- ists in the intestines may cause erosions of the mucous membrane or may perhaps burrow a.slight distance into the wall, a condition which approx- imates the action of the larvae in passing through the wall; accordingly at some point the distinc- tion between infestation and infection becomes an arbitrary one. Confusion sometimes arises in using the words infectious and contagious. A contagious disease is one which may be transmitted from one indi- vidual to another by direct or indirect contact; the.word has reference to the manner of transmis- sion of an infection. Non-infectious diseases are never contagious. Contagiousness is well illus- trated in those disease in which the transmission takes place through the air, as seems to be the case in smallpox and scarlet fever. Here there may be a contagious zone of atmosphere surround- ing the patient, in which the virus is present, and