[5] When cysts are swallowed, they cause infections by excysting (releasing the trophozoite stage) in the digestive tract.

[6][7] Symptoms can include fulminating dysentery, bloody diarrhea, weight loss, fatigue, abdominal pain, and amoeboma.

[12] E. histolytica is also recognized as an emerging sexually transmissible pathogen, especially in male homosexual relations, causing outbreaks in non-endemic regions.

This similarity with bacterial protein indicates that transposable elements have been acquired from prokaryotes by horizontal gene transfer in this protozoan parasite.

[24] A burst of research on viruses of E. histolytica stems from a series of papers published by Diamond et al. from 1972 to 1979.

In 1972, they hypothesized two separate polyhedral and filamentous viral strains within E. histolytica that caused cell lysis.

E. histolytica induces tissue damage by three main events: direct host cell death, inflammation, and parasite invasion.

Once the trophozoites are excysted in the terminal ileum region, they colonize the large bowel, remaining on the surface of the mucus layer and feeding on bacteria and food particles.

The parasite has several enzymes such as pore-forming proteins, lipases, and cysteine proteases, which are normally used to digest bacteria in food vacuoles but which can cause lysis of the epithelial cells by inducing cellular necrosis and apoptosis when the trophozoite comes in contact with them and binds via the lectin.

A blood test is also available, but it is recommended only when a healthcare provider believes the infection may have spread beyond the intestine to some other organ of the body, such as the liver.

Since they have little effect on amoeba cysts, usually this treatment is followed by an agent (such as paromomycin or diloxanide furoate) that acts on the organism in the lumen.

[2] In addition to targeting organisms in solid tissue, primarily with drugs like metronidazole and chloroquine, treatment of liver abscess must include agents that act in the lumen of the intestine (as in the preceding paragraph) to avoid re-invasion.

[29] People without symptoms, otherwise known as asymptomatic carriers, in non-endemic areas, should be treated with paromomycin; other treatments include diloxanide furoate, and iodoquinol.

[citation needed] In sexually reproducing eukaryotes, homologous recombination (HR) ordinarily occurs during meiosis.

[33] The DNA pairing and strand exchange reactions are enhanced by the eukaryotic meiosis-specific recombination accessory factor (heterodimer) Hop2-Mnd1.

[34] HR is enhanced under stressful growth conditions (serum starvation) concomitant with the up-regulation of HR-related genes.