Protozoan Parasites of the Small Intestine

Protozoan parasites of the small intestine are most common in areas where unhealthy water supply, inadequate sanitation, and overcrowding are present. Infection rates are highest in infants and young children and predominantly among immunocompromised individuals. Infection is mainly through consumption of foods and drinks contaminated with the infective stages, flies, food handlers, and autoinfection. Protozoan parasites of the small intestine are associated with a variety of symptoms and signs as follows: abdominal colic and discomfort, infantile diarrhea, severe or even fatal intractable diarrhea, nausea, vomiting, vitamin deficiencies, and fatty dyspepsia, and also, dehydration, anemia, malnutrition, and indigestion. The following are the commonest protozoan parasites infecting the small intestine: