Many intestinal protozoa parasites inhabit the gastrointestinal tract of humans. Among the total of 256 samples collected between the ages of 0–50 yrs, 194 samples were positive. Standard laboratory techniques for parasitological diagnosis were carried out for each sample. Entamoeba coli (23%), Cyclospora sp. (22.2%), Entamoeba histolytica (21.8%), Giardia intestinalis (14.4%), Ascaris lumbricoides (6.2%), Trichuris trichiura (1.1%), and Hymenolepis nana (2.7%) were found in the dwellers of low socioeconomic areas.
Asymptomatic human infections are usually diagnosed by finding cysts shed in the stool. Various flotation or sedimentation procedures have been developed to recover the cysts from fecal matter and stains help to visualize the isolated cysts for microscopic examination. Serological tests exist and most individuals will test positive for the presence of antibodies. Good sanitary practice, as well as responsible sewage disposal or treatment, are necessary for the prevention of E.histolytica infection on an endemic level. E.histolytica cysts are usually resistant to chlorination, therefore sedimentation and filtration of water supplies are necessary to reduce the incidence of infection.