Dysentery is pre-eminently a disease of army life, its victims among soldiers numbering more than all other diseases together. Sir James MacGrigor, Medical Superintendent of the British army, called it the scourge of armies and the most fatal of all their diseases. Aitken says that "it has followed the tracks of all the great armies which have traversed Europe during the continental wars of the past two hundred years." It decimated the French, Prussian, and Austrian armies in 1792. In Cape Colony in 1804 every fourth man among the soldiers was attacked with the disease, and of those attacked every fifth man died. In Napoleon's campaign in Egypt dysentery numbered one-half more victims than the plague; Kinglake says that 5000 men died of dysentery alone in the war of the Crimea; and in our own country during our Civil War from 1861-65 chronic camp dysentery was the cause of more than one-fourth of all the diseases reported, the mortality being at the rate of 12.36 per 1000.
Woodward relates that the dysenteries, acute and chronic, with diarrhoeas, made their appearance in the new regiments at the beginning of the war, and, though mild at first, quickly assumed a formidable character. "Soon no army could move without leaving behind it a host of the victims. They crowded the ambulance-trains, the railroad-cars, the steamboats. In the general hospitals they were often more numerous than the sick from all other diseases, and rivalled the wounded in multitude. They abounded in the convalescent camps, and formed a large proportion of those discharged for disability." Most of the prisoners died of this disease, and great numbers succumbed to it on retirement to their homes after the cessation of the war. It is the story of many a campaign, Eichhorst says, that dysentery kills more men than the enemy's guns.
The fact that it sometimes shows itself in periodic form or with periodic exacerbation, that it is sometimes successfully treated with quinia, and that, as has been noticed from the days of Hippocrates down, it prevails in greatest intensity in malarial regions, has given rise to the view that dysentery is a malarial disease. This view, which was strongly advocated by many of the older writers, Senac, Fournier, Annesley, met with renewed support at the hands of many of the surgeons in our Civil War. But wider observation has shown the fallacy of such a view; for not only may the diseases prevail entirely independently of each other in malarial regions, but there are regions where one does and the other does not exist. Thus Huebner quotes from Rollo concerning St. Lucie (West Indies), a town situated on a mountain in the midst of a swampy country in which both dysentery and malaria abound, while the town itself is almost free from dysentery; and Dutrolan cites Réunion as a place where marsh fevers do not occur, while dysentery is very common. Bérenger-Féraud2 scouts the idea of any such connection. "Let us mention only St. Pierre de la Martinique," he says, "where there is not a piece of marsh as big as a hand, but where dysentery has made great ravage more than once. We might cite also Mauritius, Gibraltar, Malta, New Caledonia—places exempt, or almost exempt, from malaria, but often visited by dysentery."
2 Traité théorique et clinique de la Dysenterie, etc., Paris, 1883.
The view that dysentery is a form of typhus or typhoid fever (Eisenmann) or scurvy needs no refutation in the light of existing knowledge regarding the pathogenesis and pathology of these affections. These diseases may often complicate, but can never cause, dysentery.
Dysentery is a disease which spares no age, sex, or social condition, the seeming greater suffering of the poorer classes being due to the filth, food, darkness, dampness—in short, to the bad sanitation—of poverty.
Though the disease is often confined exclusively to soldiers in the midst of a civil population, examples are not wanting of an exclusive selection of civilians or of an indiscriminate attack in every direction. Lastly, dysentery is a disease which may recur repeatedly in the same individual, one attack rather predisposing to than preventing another.
ETIOLOGY.—Dysentery is an omnipresent disease. "Wherever man is," Ayres observed of it nearly a quarter of a century ago, "there will some of its forms appear." But the character of the form, and more especially the extent and severity of the disease, vary in extreme degree with the conditions surrounding the abode of man. No one of these conditions affects the disease so markedly as the climate. It is the testimony of Hirsch, based upon the study of seven hundred epidemics of the disease, that no other disease is so dependent upon the influence of the climate. The home of dysentery is the tropical zone. It prevails in greatest frequency and virulence in the tropics, and in those regions of the tropics where the characteristics of this zone are more pronounced, diminishes in intensity in the temperate regions, and occurs only in sporadic form farther north. At 40° latitude the line may be pretty sharply drawn; beyond it dysentery as an epidemic is almost unknown.3
3 Shakespeare (Troilus and Cressida) cites "griping of the guts" among the "rotten diseases of the south."
India has been from time immemorial the hotbed of this disease. Henderson says it is perhaps more fatal to natives than all other diseases put together, and Hutchinson, Hunter, and Tytler observe that it causes three-fourths of the deaths among the natives of Hindostan. In Egypt the disease is indigenous, and is, according to Frank, post pestem maxime timendus. Greisinger reports that one-half of all the autopsies made by him in Egypt showed dysentery as a primary or secondary affection. It is epidemic here at all times, Roser says, and all fatal cases of acute or chronic disease finally perish with it.