Entamoeba dispar is a non-pathogenic commensal of the human gastrointestinal tract which is morphologically and microscopically identical to pathogenic Entamoeba histolytica. Therefore, to confirm the infection with dysentery, molecular tests must be performed to distinguish the type of infection.
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The genus Entamoeba comprises six species (Entamoeba histolytica, Entamoeba dispar, Entamoeba moshkovskii, Entamoeba poleki, Entamoeba coli, and Entamoeba hartmanni) that live in the human intestinal lumen.
The protozoan Entamoeba histolytica is the causative agent of amebiasis. There are approximately 50 million cases of amebiasis per year worldwide, and it kills nearly 100 thousand people annually. Amebiasis is the most severe disease caused by protozoans that afflict the human intestine and the second leading cause of death among parasitic diseases It is characterized by two major clinical syndromes, amebic colitis, and amebic liver abscess.
Although E. histolytica is the only one recognized as a pathogen, the ability of the other species to cause disease is unclear. In fact, specific strains of E. dispar have been associated with non-dysenteric human colitis and amoebic liver abscess, therefore the non-pathogenicity of E. dispar is questionable.
The diagnosis of amebiasis caused by Entamoeba histolytica has been primarily based on microscopic examination of stools. However, fails to differentiate from other parasites as E. dispar, which is perhaps 10 times more common worldwide.
For the laboratory documentation of the presence of the amoeba E. dispar, the polymerase chain reaction (PCR) might be a method of choice due to sensitivity and specificity and even it has been strongly endorsed by the World Health Organization (WHO).
