Volume 1

The Lettsomian lectures on dysentery : delivered before the Medical Society of London, 1914 / by F.M. Sandwith, M.D. Durh., F.R.C.P. Lond., Gresham Professor of physic; lecturer on tropical diseases, St. Thomas's Hospital.

  • Sandwith, Fleming Mant, 1853-1918
Date:
[1914]
Catalogue details

Licence: Public Domain Mark

Credit: The Lettsomian lectures on dysentery : delivered before the Medical Society of London, 1914 / by F.M. Sandwith, M.D. Durh., F.R.C.P. Lond., Gresham Professor of physic; lecturer on tropical diseases, St. Thomas's Hospital. Source: Wellcome Collection.

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    they are always liable to relapse, the “ minuta ” forms of the entamoebae giving place to the large active tissue-invading forms (“histolytica” forms), which begin again their destruction of the wall of the large intestine; but they are exceedingly dangerous to other people, in that they may be distributing broadcast the infective cysts, which have only to gain entrance to the intestine, in the food or water, to bring about infection. Such individuals are, in fact, infinitely more dangerous than those who are suffering from acute dysentery and who are passing only the large non-infective “ histolytica” forms. It is not known with certainty exactly how long such “ convalescent carriers” may harbour the “ minuta” forms of the pathogenic entamoeba without themselves suffering a relapse of their old symptoms or ridding them¬ selves of their infection. It may at least be for a period of several months. Walker and Sellards have described, under the name of “ contact carrier,” another type of indi¬ vidual who is found to be infected with the “ minuta ” generation without ever having suffered from amoebic dysentery. They suppose that such persons have become infected by ingesting encysted forms, but that the entamoebae, for some reason not understood, have not invaded the tissues and have remained in the cavity of the intestine as “minuta” forms, which reproduce there and encyst as in the “convalescent carriers.” It may be concluded, therefore, that from the point of view of the already infected individual, the free entamoebae are of importance because they are the tissue-invading forms, but that from the point of view of spread and dissemination of the disease the cysts only are to be feared. With a little experience it is easy to recognise and identify in faeces the encysted forms of either Entamoeba coli or Entamoeba dysenteriae, but the identification of the free unencysted forms presents much greater difficulties, even to the expert.