Protozoan Parasites of the Large Intestine

Protozoan parasites of the large intestine like other parasitic infections are most common in areas where poor water supply, inadequate sanitation, and overcrowding are present. Infection rates are highest in children in camps and slums and among immunocompromised individuals. Infection is mainly through consumption of foods and drinks contaminated with the infective stages. Using human manure as fertilizer, flies and food handlers (carriers) are very crucial in the spread and transmission of the intestinal protozoan infections. Generally speaking, protozoan parasites infecting the large intestine are responsible of bloody stools, intestinal ulceration, amebic dysentery, and/or constipation. Protozoan parasites of the large intestine are associated with a variety of symptoms and signs as follows: abdominal colic, tenesmus, discomfort, frequency, nausea, and vomiting, and also, malnutrition and indigestion. The following are the commonest protozoan parasites infecting the large intestine: