DYSENTERY

infectious disorder characterized by inflammation of the intestine, abdominal pain and straining, and diarrhea with stools that often contain blood and mucus. There are two major types of dysentery: bacillary and amebic, caused, respectively, by bacteria and amoebas. Bacillary dysentery, or shigellosis, is caused by bacilli of the genus Shigella. Symptomatically, the disease ranges from a mild attack to a suddenly commencing severe course ending in death caused by dehydration and poisoning by the bacterial toxins. After an incubation period of one to six days, the disease has an abrupt onset with fever and the frequent production of watery stools that may contain blood. Straining and vomiting may also occur, and dehydration soon becomes obvious owing to the copious loss of body fluids. In advanced stages of the disease, chronic ulceration of the large intestine causes the production of bloody stools. The most severe bacillary infections are caused by Shigella shigae (also called S. dysenteriae type 1), which is found chiefly in tropical and subtropical regions. S. flexneri, S. sonnei, and S. boydii are other Shigella bacilli that cause dysentery. The treatment of bacillary dysentery is based on the use of such antibiotic drugs as tetracycline, oxytetracycline, and chlortetracycline. The copious administration of fluids and, in some cases, blood transfusions may be necessary in cases where the patient is severely dehydrated. Amebic dysentery, or intestinal amebiasis, is caused by the protozoan Entamoeba histolytica. This form of dysentery is usually much more chronic and insidious than is the bacillary disease and is more difficult to treat because the causative organism occurs in two forms, a motile one and a cyst, each of which produces a different disease course. The motile form causes an acute dysentery, the symptoms of which resemble those of bacillary dysentery. The cyst form produces a chronic illness marked by intermittent episodes of diarrhea and stomach cramps or other abdominal pains. Bloody stools occur in some patients. The chronic type is much the more common of the two and is marked by frequent remissions and exacerbations of symptoms. The chronic form may also produce ulcerations of the large intestine. Both forms of amoebic dysentery are treated with emetine, diodoquin, and other drugs that specifically kill the amoebic parasites that thrive in the intestines. The transmission of both bacterial and amebic dysentery occurs through the ingestion of food or water that have been contaminated by the feces of a human carrier of the infective organism. The transmission is often by infected individuals who handle food with unwashed hands. The spread of amebic dysentery is often accomplished by people who are carriers of the disease but who currently show no symptoms. Dysentery is commonly found when people are crowded together and have access only to primitive sanitary facilities. It is one of the typical diseases found in prisoner-of-war camps, especially those in tropical climates.