Dysentery
Two forms of dysentery are known, bacillary, or bacterial dysentery and amoebic dysentery. Both are widespread throughout the world and have been known since ancient times. An Egyptian manuscript from about 1550 B.C., for example, recounts a legend in which a dysentery-like disorder afflicts Horus, son of Isis and Osiris.
The disease has been particularly associated with warfare. During the Civil War, nearly as many soldiers died of dysentery as were killed in action. Improvements in sanitation methods in the twentieth century have changed the pattern of the disease. It is now much less common in industrialized nations while still remaining a major health problem in many parts of Africa, Asia, and Central America.
Dysentery is characterized by loose and frequent stools that often contain blood, inflammation of the intestine, abdominal pain, and intestinal ulceration. Left untreated, either form of dysentery may result in death as a result of dehydration or toxins released by the infectious agents.
The etiology of bacterial dysentery was first recognized in 1898 by the Japanese physician, Kiyoshi Shiga (1870-1957). Shiga was a pupil of Japan's most famous bacteriologist, Shibasaburo Kitasato. During an outbreak of the disease in Japan, Shiga isolated the causative agent, a bacterium later named in his honor, Shigella shigae. The organism is also called Shigella dysenteriae. During World War I, other forms of the agent--S. boydii, S. flexneri, and S. sonnei--were also discovered.
Amoebic dysentery was first recognized in 1875 when Frederick Lösch (1840-1875) detected it in the stools of a Russian peasant. The disease was most completely described in an 1891 report, "Amoebic dysentery," written by the American researchers Henri Amedee Lafleur and William Thomas Councilman (1854-1933).
Credit for the identification of the causative agent of amoebic dysentery is usually given to the German zoologist, Fritz Richard Schaudin (1871-1906). During his research on tropical diseases, Schaudin found that amoebic dysentery is caused by the protozoan Entamoeba histolytica. The organism is very similar to another protozoan, Entamoeba coli, which is harmless. Schaudin demonstrated the difference between the two organisms and the pathogenicity of the former by injecting himself with both and observing their effects.
Dysentery is most likely spread through person-to-person contact and through contaminated water and food. Although largely under control, dysentery epidemics still occur. A primary difficulty in controlling dysentery epidemics is that the organism that causes Shigella dysenteriae can quickly build a resistance to antimicrobial drugs. The primary ways to prevent dysentery is through personal, domestic, and environmental hygiene approaches such as washing hands after defecation and before handling food, using clean drinking water, and disposing of faeces safely. The best approach for stopping an epidemic is to identify it early so that the appropriate health care measures can be taken, including widespread administration of an antibiotic.
This is the complete article, containing 452 words
(approx. 2 pages at 300 words per page).
