Prevalence of Entamoeba histolytica and Entamoeba dispar in a Highly Endemic Rural Population

Abstract

Amebiasis is caused by the protozoan Entamoeba histolytica. This disease, or the asymptomatic infection, is associated with poor socioeconomic conditions, malnutrition, and poor hygiene behavior, all common in developing countries. There is evidence of the existence of two species of quadrinucleated amebas in the human population ( E. histolytica and Entamoeba dispar ) with different pathogenic capabilities, making necessary the reevaluation of the actual frequency of infection and disease, because is a tendency to overestimate it in endemic areas where other intestinal infections causative of dysentery or bloody diarrhea are found. The opposite is frequent in nonendemic areas, where the presence of amebas is overlooked in stool microscopic examination. In the present work, we studied the prevalence of E. histolytica or E. dispar infection in the rural community of Coahuixtla, State of Morelos, Mexico. The selection of this community was made on the basis of the reported rate of new cases of intestinal amebiasis or amebic liver abscess in the state of Morelos (1). E. histolytica and E. dispar identification was performed through the molecular analysis of the cysts isolated directly from stool samples.