On human entozoa : comprising the description of the different species of worms found in the intestines and other parts of the human body, and the pathology and treatment of the various affections produced by their presence : to which is added a glossary of the principal terms employed / by Wm. Abbotts Smith.

Date:
1863
Catalogue details

Licence: Public Domain Mark

Credit: On human entozoa : comprising the description of the different species of worms found in the intestines and other parts of the human body, and the pathology and treatment of the various affections produced by their presence : to which is added a glossary of the principal terms employed / by Wm. Abbotts Smith. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

    99/268 (page 87)
    Under conditions which have not yet been satisfactorily determined, lumbrici may appear epide- mically, or they may be endemically established in a certain district. The writers of the last century frequently refer to epidemics of fever or of dysentery, connected with the presence of] entozoa. When we endeavour to ascertain the conditions which determine the rarity of the ascaris lumbricoides in some localities, and its frequency in another, or its appearance in a large number of cases, epidemically as it were, it is especially requisite to recollect that this entozoon proceeds from an ovum, and that this ovum, after it has been expelled with the evacuations, must again enter the human intestine before it can become developed. It is consequently necessary to find out how the ovum is conveyed into the situation proper for its development. This is done, says Dr. Davaine, not by means of legumes, nor of fruit, nor of bad diet, but through the medium of the water which is used for drinking purposes. The ova of the lumbrici are expelled with the evacua- tions, which contain them in immense numbers. These ova may remain in the waters of a marsh, of a river, or of a well, during six or even more months without undergoing any change; the embryo which becomes developed during this period is not set at liberty until the ovum again enters the human intes- tine. The use of a filter would separate the ovum from the water; exposure to a»high temperature would kill it. With these data, it will be possible to account for the circumstance of these worms being so rare in large cities, which have a properly regulated supply