Cholera (Fr. choléra asiatique). The Greek word cholera (connected with cholē, 'bile,' as is also the English 'choler') was used by both Hippocrates and Celsus to describe sporadic cholera (see below). The term is now rather loosely employed to denote various forms of disease (such as chicken cholera, for which see POULTRY). In this article it is used as the designation for Asiatic, Oriental, or Epidemic Cholera, otherwise called Cholera Morbus or Pestilential Cholera. This disease has been popularly believed to be a new disease which made its first appearance in Bundelkhand in 1817, when 5000 men died in five days; but there is no doubt that it has a far more ancient origin, and has visited Europe since 1500 A.D. Cholera is a specific disease characterised by violent vomiting and purging, with rice-water evacuations, cramps, and collapse; tending to run a rapidly fatal course, and capable of being communicated from person to person by means of the dejecta of patients suffering from it. The mortality of cholera varies in different epidemics; it is always greatest at the commencement of a fresh outbreak; at the lowest estimate one-half of the persons attacked die. Cholera has been endemic for centuries in certain parts of India, especially in the valley of the Ganges, and in the 19th century it has spread on various occasions almost all over the civilised world. In 1817-23 cholera spread rapidly throughout Bengal and other parts of India, Ceylon, Burma, and China, slaying thousands of victims. A second outbreak occurred from 1826-37, and spread viâ Central Asia and Russia with frightful virulence throughout Europe and America. From Riga it was imported to Sunderland (26th October 1831); from Hamburg to London (13th February 1832); and so it passed on to Paris, Quebec, Chicago, New Orleans, &c. In 1846-63 a third epidemic occurred, and Europe and America were again visited; 53,293 persons dying in England and Wales in 1848-49, and 20,097 in 1854. A very extensive outbreak took place in 1865-75; and in 1884-85 cholera reached France (especially Toulon and Marseilles), Italy (especially Naples), and Spain. The epidemic of 1892 was specially severe in the previously famine-stricken districts of Russia, where it carried off 220,000 victims, and in Hamburg, where of 17,000 stricken 10,901 died. The outbursts of cholera are generally sudden in their advent, hundreds of people being attacked within a few days.
Certain factors determine the origin and promote the diffusion of cholera. Places having a high altitude are prone to escape its ravages (at any rate for a long time), whereas low-lying ground favours its spread. During the general diffusion of cholera in India in 1817-19, the hill-forts remained exempt in a remarkable way, while the disease was prevalent in the plains around. There is no doubt too that cholera follows the rivers; and the more copious the saturation of the ground, and the greater the amount of organic matter undergoing decomposition it contains, the more extensive will be its spread. The drying of the soil after it has been soaked is very favourable for the development of cholera epidemics; and they are also favoured by certain physical characteristics of the soil, such as permeability to water and air, also by rocks that have a capacity for retaining moisture, and by organic detritus. But these are not the only factors we have to take into account, for climatic influences, such as heat and moisture, also affect its epidemic spread. Heat aids its production; a marked fall in the temperature and heavy rain stay its ravages, but rain after a prolonged drought often gives it impetus.
As to the exact nature of the morbid poison which causes cholera, authorities still differ, yet in all probability a germ found in 1883 by Koch in the dejecta of cholera patients in Egypt, Calcutta, and Toulon, and named by him the 'Comma' bacillus, constitutes the morbid agent. His observations were to some extent confirmed by the researches of Klein and Gibbs in Calcutta and Bombay, and numbers of observers, notably Dr Macleod and Mr Miller at Shanghai in 1885, have since found the bacillus in the stools of cholera patients (see BACTERIA, GERM THEORY). The importance of this discovery can be estimated by the following fact. An Italian emigrant steamer arrived at New York in 1887, having on board a case of diarrhea, the symptoms of which were suspicious but not perfectly typical of Asiatic cholera. Cultivation experiments were made at the Carnegie Laboratory of material discharged by this patient, and in four days they manifested the characteristic appearances due to the growth of the 'Comma' bacillus; and the diagnosis was subsequently confirmed by the occurrence of cases amongst the ship's passengers, in which the unmistakable symptoms of Asiatic cholera were present. It must, however, be said that bacilli similar to these do occur in healthy persons; they do not, however, give rise to the same appearance when cultivated by Koch's method as do the bacilli found in cholera stools. Further research is necessary to show in what way these bacilli cause cholera. The dejecta of cholera patients when perfectly fresh are innocuous, but very soon they develop the morbid agent, and water, food, or clothing contaminated by them will communicate the disease to healthy persons. Numerous observations go to prove that the wind also is capable of conveying the poison from dried cholera stools, but how far it is impossible to say. Troops or pilgrims may carry the infection and propagate it along their line of march; if healthy bodies of men meet with infected troops or enter a tainted district, they will almost certainly suffer; or if a body of men encamp on a site recently occupied by cholera patients, they will become affected. If cholera breaks out on board ship in mid-ocean, it will be coincident with the exposure of some part of the cargo from an affected place.
Causes.—(a) Predisposing.—Fear or shock, exposure to sudden changes of temperature, intemperance in labour, pleasure, or drink, and want of proper clothing, as well as everything which tends to derange the stomach, or the use of strong purgatives, predispose a person to an attack of cholera; and fresh arrival into an infected area renders a person extremely liable to an attack. (b) Exciting.—This is of course the entrance into the body of the poison, which may be introduced into the system either by drinking-water, or by food contaminated with the discharge of a cholera patient. It may also be inhaled as dust, and enter the body through the lungs. There can be no doubt that polluted drinking-water is by far the most common source of infection; and it has been noticed, as for instance in Calcutta, that the improvement in the water-supply has greatly diminished the prevalence of cholera.
Symptoms.—After some premonitory symptoms characterised by malaise, depression, and slight diarrhoea, cholera commences by purging, to be soon followed by vomiting and painful cramps in the stomach and limbs. These symptoms form the first or evacuation stage. The discharges downwards are extremely copious, and they soon become colourless and turbid, resembling water in which rice has been boiled; hence the expression, 'rice-water' evacuations. In the second stage, which is called the 'algid' stage, there is profound collapse. In this condition the patient lies motionless and apathetic, except when tormented by cramps, which are of frequent occurrence. The surface temperature of the body falls to 95° F., or even lower. The pulse becomes almost imperceptible, and the respirations are shallow and rapid, the air expired being cold, and the voice a hollow, husky whisper. The nervous system suffers severely, and muscular prostration is well marked. The features assume a leaden or livid hue; they are pinched and shrunken. The nose becomes sharp and pointed, the cheeks hollow, and the eyeballs, which are often bloodshot, sink in their sockets and are nearly hidden by the half-closed lids. The surface of the body, especially the extremities, is bluish, wrinkled and shrivelled, and bathed in cold clammy sweat. For a time the mind is clear but inactive; in fatal cases, however, stupor sets in, followed by coma; thirst is intense. In this stage assimilation and secretion are in abeyance; all the vital processes in fact are brought almost to a standstill. This stage may last from twelve to thirty-six hours, when the third stage, that of reaction, gradually commences. Heat returns to the surface of the body, the breathing becomes regular and calm, the secretions are re-established, the pulse improves, and the patient will fall into a calm sleep. This stage may terminate in speedy convalescence, but such is not always the case, as a relapse may take place and certain complications and sequelæ follow. The most dreaded of these are suppression of urine, nremia, and fever, often closely resembling typhoid, and constituting, at least in the temperate zone, one of the chief dangers in the progress of cholera. Disease of the kidneys, inflammation of the lungs, ulceration of the cornea, abscesses all over the body, and hemorrhage from the bowels may also occur. The mortality varies very much: it may be from one in four of those attacked to three in four. In some epidemics in India it is not more than 15 per cent. of those attacked; in others as high as 90 per cent. In 1885 it was announced that of 233,546 persons attacked in Spain during the recent visitation, 82,619 succumbed. One attack of cholera does not confer protection against another.
Treatment.—With regard to treatment, medicines are almost powerless, and many of the vaunted remedies undoubtedly do far more harm than good. It is, however, necessary to try to check the premonitory diarrhoea, as by so doing in many cases the disease may be cut short. The slightest symptoms of diarrhoea should be attended to; the patient should be put to bed, a mustard plaster should be applied to his abdomen, and opium in some form or other should be administered. A favourite prescription is four grains of acetate of lead with one of opium, which may be given after each loose stool until three doses have been taken; or else thirty drops of laudanum in half a glass of brandy in hot water. In the state of collapse it is useless or even injurious to give medicine, but soda-water and ice may be administered to relieve thirst. During collapse the medicines could not be assimilated, and if given then, during reaction they would be absorbed and do harm. As soon as reaction occurs, thin water-arrowroot should be given in small quantities, and then iced milk, chicken-tea, and beef-tea, as the stomach can stand it, and enemata of beef-tea should be given every four hours.
The true remedy against cholera is undoubtedly prevention. The greatest care should be taken to secure pure drinking-water, which should be boiled before use, and uncontaminated food. Personal cleanliness, free ventilation, and thorough disinfection of the drains should be enjoined. With regard to quarantine, it is worse than useless in checking the spread of cholera; but all persons coming from an infected area who have the slightest tendency to diarrhoea should be isolated and carefully watched. It should be remembered with what ease cholera can be conveyed by clothing, and therefore the importation of all rags and old clothes should be prohibited. Lastly, the destruction of the discharges from cholera patients, and of the linen soiled by them, is of the utmost importance. The dead should be buried immediately, with due precautions. A Spanish physician, Dr Ferran, employed preventive inoculation in 1885; his methods, however, were discredited. But in 1893-95 Dr Haffkine, a Russian scientist, had performed in Bengal alone 42,445 inoculations against cholera without mishap and with great preventive efficiency. In the Gangetic valley—the home of cholera—the Comma bacillus is a constant feature in the malady.
Cholera Sicca is a rare form, in which symptoms of collapse occur, with great coldness and blueness of the surface, and death takes place in a few hours, without any purging.
Cholera Nostras is also called Simple Cholera, Summer Cholera, British Cholera, Sporadic Cholera, Choleraic Diarrhoea. This is an acute catarrhal affection of the mucous membrane of the stomach and small intestines, which usually occurs in late summer or early autumn. It is attended by vomiting and purging of bile, cramps and pain in the bowels, the whole system being implicated on account of the rapid loss of water from the body. This disease, although severe, is usually only fatal to young infants or to old or debilitated persons. Simple cholera is treated like Diarrhoea (q.v.).
Asiatic Cholera is regarded as distinctly a 'dirt disease,' and the great religious pilgrimages of the East have had much to do with conveying the poison from places where it is endemic, and distributing it widely. The sanitary measures adopted at Hardwar on the Ganges have proved as strikingly effective as those employed in England to control the invasions of 1892 and 1893. But though some attempts have been made to reduce the risks attendant on the Mecca pilgrimages (where the wells are a great source of infection), effective measures have as yet proved impossible.
See Pettenkofer's Cholera: How to Prevent and Resist it (Eng. trans. 1884); Stillé's Cholera (Phila. 1885); Bellow's History of the Cholera in India (1884); and Macnamara's Asiatic Cholera (1892).