EJMS

Abstract

Acute diarrheal illness is a major worldwide problem; it is one of the five leading causes of mortality each year. Parasitic infections of the colon are big problem in the developing world and common in Western countries. Most of the infections and mortality from these diseases occur in the developing world in rural regions. However, these diseases have become more common in Western countries and in big cities over the past 30 years. These changes in the disease patterns can be attributed to emigration from the third world to developed countries and migration of rural populations to the big cities in developing nations. These parasitic infections have protean manifestations and consequences. The medical problems range from chronic asymptomatic carrier to fulminant infections and even death. Several factors such as the host immune status, the infecting organism, and the availability of treatment play key roles in the outcomes of parasitic colitis. The two major classes of parasites causing these infections are the protozoa (Entamoeba histolytica, Giardia lamblia, Cryptosporidium, Isospora, Cyclospora, Balantidium coli and Trypanosoma cruzi,) and the helminths (Schistosoma, Strongyloides, Ascaris, Trichuris and Enterobius). This article summarizes the silent features of each parasite with respect to epidemiology, transmission, pathogenesis, clinical features, diagnosis, and treatment. The vast majority of these infections have a self-limited clinical course or are easily treated with medical management, while surgery is rarely needed.