Cholera

Cholera (Gk. chote, the bile). Cholera morbus, Asiatic cholera, or malignant cholera is a specific epidemic disease, the main symptoms of which are sudden collapse with vomiting and diarrhoea. Cholera nostras, or English cholera, is a term applied to the more severe sporadic cases of diarrhoea which occur in Great Britain in the summer months, quite apart from any visitation of the epidemic disease. Cholera despoules, or "fowl cholera," is an affection met with in poultry-yards, the symptoms of which bear some resemblance to the cholera morbus as seen in man.

History. The disease has probably existed for centuries in India. It particularly affects certain regions, as, for example, the delta of the Ganges. In such situations isolated cases of cholera occur from time to time, and, at length, when the conditions for spreading become favourable, an epidemic wave of the disease is developed, and the ravages of cholera extend and involve far distant countries. Such an epidemic was that which commenced in India in 1817, and then slowly extending wrought great havoc in the succeeding years in almost all parts of the globe. The dates at which epidemics have commenced in this country are as follows: - 1831, 1848, 1853, and 1865. In each instance the cholera was traceable to infected persons landing in seaport towns; the early attacks have usually occurred in the autumn of the year specified, and the epidemic, after smouldering through the winter, has burst forth and attained its greatest height, throughout the country, in the summer of the succeeding year, and has then entirely disappeared.

Causation. As regards the conditions which favour the development and spread of the cholera poison, it is clear that heat and climate have some influence in the matter; low-lying ground, too, is more often affected than places situated on an altitude. According to Pettenkofer, the height of the ground water plays an important part in determining outbreaks; he maintains that the cholera poison develops most malignantly where the soil is porous, and a rise in the level of the ground water has rendered it moist, and a subsequent fall has served to aerate it. Dr. Snow in 1849 adduced weighty evidence to show that the disease was spread by the contamination of drinking water with choleraic evacuations, and facts which seem to support this conclusion have been forthcoming ever since. Some authorities, however, still oppose this view. Suspicion having once settled on the cholera stools as the means of spreading the infection, attention was directed to a careful examination of the evacuations of patients, and many attempts were made to establish the existence of a cholera germ in the excreta. All previous efforts in this direction have been eclipsed by the discovery in 1884 of the comma bacillus by Robert Koch. Numerous observers have satisfied themselves that it is an almost invariable rule to find Koch's bacillus in the intestinal discharges of cholera patients; unfortunately, however, it has not hitherto been found possible to obtain very conclusive experimental proof of a cause and effect relationship between the bacillus and the disease.

Symptoms. After a short incubation period, in which some premonitory malaise and diarrhoea may be present, the actual attack of the disease is usually ushered in by intense purging. The evacuations quickly assume a thin, colourless, odourless character, to which the expression "rice-water stool" has been applied, vomiting is usually present, and the vomited matter after a while assumes the rice-water appearance. The loss of fluid by the diarrhoea and vomiting combined is very great, and quickly leads to a shrunken appearance particularly noticeable in the sunken eyes and shrivelled extremities. Intense muscular cramps are usually complained of, the temperature falls, and the patient is rapidly reduced to a condition of extreme collapse. Thus the initial stage passes into the so-called "algide stage" of cholera, in which purging and vomiting often cease, and the helpless victim of the disease lies cold and livid, and, in fatal cases, rapidly becomes comatose and dies. If the attack be a milder one, after some twenty-four hours or less a period of reaction sets in, temperature rises, the secretions become re-established, and a febrile condition generally ensues, from which recovery may either speedily or after some days' interval occur, or, again, the reactionary symptoms may lead to a fatal termination. The rate of mortality of cholera cases is always high: rarely less than 25 per cent., sometimes much more considerable.

Treatment. There is no known specific treatment of any avail in the disease. All that can be done is to treat symptoms as they present themselves. In the stage of collapse the injection of saline solutions into the veins has sometimes been attended with success. The treatment par excellence of cholera is preventive treatment. The improved sanitary conditions which have been brought about in Great Britain are held by the best authorities to have rendered the fear of a formidable epidemic a thing of the past. Cholera can obtain no hold upon a district which has a pure water supply, good drainage, and satisfactory hygienic surroundings. It is a wise precaution, if cases of the disease occur, to boil all water before use, and scrupulous disinfection of the excreta of patients and destruction of soiled clothing should be enforced. Quarantine is quite useless as a means of prevention if the conditions necessary for the spread of the disease exist; the most rigid quarantine will be powerless to prevent the introduction of the poison, and therefore powerless to prevent its diffusion. All cholera-infected vessels arriving in British ports are dealt with under an order of the Local Government Board which provides for medical inspection, isolation of declared and doubtful cases of the disease, and disinfection. Passengers who present no symptoms of the disease are allowed to proceed to their destination, their names and addresses being transmitted to the medical officer of the district for which they are bound.