The two agencies by which it is most fre quently conveyed are house flies, which carry the bacilli directly from the deject° of cholera patients to milk and other food, and water which is constantly polluted in the countries in which cholera is present. Military camps and barracks are notorious breeding places for cholera. In certain parts of India the water for bathing is also used for drinking purposes and it seems impossible to prevent the natives from thus using it and from suffering the inevitable consequences.
Melville ((Military Hygiene and Sanita tion,) 1912) states that cholera has disap peared from the British army in India since the water supply has been improved and regu lated. The disease is seldom conveyed by the air; its development is favored at the sea-level, by a moist soil, and by a high temperature. It is common to all ages and usually attacks the debilitated in preference to the robust.
Pathological Anatomy of Cholera.— After death the stomach contains more or less of the whey-like albuminous fluid and is full of cast off epithelium. The small intestines usually contain a large quantity of the whey-like fluid and epithelium. Theglands of Brunner, the solitary and agminateof patches, are thickened and very prominent. The solitary glands of the large intestines are also infiltrated and swollen. The liver is more or less advanced in fatty de generation. The kidneys have a pale, white appearance, due to the epithelium blocking the tubes. The bladder is empty and contracted. The lungs are congested. The right cavities of the heart are distended with blood, while the left cavities are empty and contracted.
Clinical History.— When the disease runs its typical course it has three stages: (1) The preliminary or stage of invasion. (2) The stage of collapse. (3) The stage of reaction. It is preceded by a period of incubation which ordinarily lasts from two to five days.
It would seem probable, however, that dur ing a virulent epidemic when people are over come by fear, fatigue, anxiety etc., the period of incubation may in some cases be hardly appreciable.
1. In the preliminary stage there is more or less profuse diarrhoea whic.h may be ushered in abruptly and with or without fever, or it may be attended with pain, vomiting, headache, great depression of spirits, etc.
2. In the stage of collapse there is still profuse diarrhoea with pain and straining.
There is also great exhaustion and great evi dence of shack; the countenance is ghastly, there is sub-normal temperature, and a scarce perceptible pulse. This condition is frequently followed by unconsciousness and death. The stools are at first yellow from the biliary color ing matter, then whitish, resembling rice water, and they contain blood, mucus, etc., and have an alkaline reaction. The glandular secretions are arrested with the exception of those of the sweat glands; the °cold sweat° is characteristic of this stage. In nursing women the secretion of milk is sometimes maintained.
3. If the patient survives until the stage of reaction the warmth and color will gradually return to the surface, the pulse will again be come perceptible, urine will again be secreted, the stomach will become less irritable, and the stools less frequent. Relapses are not uncom mon and a patient may apparently be con valescent when suddenly his bad symptoms re turn with urzmia, unconsciousness and death. Complications are always possible. Those which occur most frequently are the typhoid condition, nephritis, pneumonia, pleurisy, ab scesses in various portions of the body, and the formation of diphtheritic membrane upon the mucous surfaces. The diagnosis of the dis ease is seldom difficult, and can almost always be made during an epidemic. The prognosis is uncertain, varying greatly with the t of the epidemic and the resisting power of individuaL The Prevention and Treatment of Cholera. — While the treatment of this disease must vary in accordance with local conditions, there are certain methods and regulations which may be regarded as generally applicable.
No specific treatment has as yet been dis covered for it, and living writers with extensive experience in India, where it has been more prevalent during the past ten years than in all the rest of the world, declare that a symptom atic and expectant plan of treatment is as good as any. Latham and English, like others who have worked among Asiatics, admit great diffi culty in carrying out preventive measures for a germ disease which is conveyed by polluted water. Natives in India simply will not take the precautions which are indispensable, in regard to water, to prevent the spread of cholera, precautions which are always neces sary when the water supply comes from storage tanks, wells, polluted rivers, etc.