Asymptomatic patients infected with E. histolytica should also be treated with iodoquinol or paromomycin, because they can infect others and because 4%–10% develop disease within a year if left untreated. Asymptomatic carriers of E. histolytica should be treated with a luminal agent to minimise the spread of disease and the risk of developing invasive disease.In patients with invasive disease, metronidazole should be used in conjunction with a luminal agent to eradicate the organism. The role of surgery is generally limited to patients with complications of invasive disease. Surgical drainage is generally unnecessary in amoebic liver abscess, as cure can be achieved with medical therapy alon
Molecular methods using the polymerase chain reaction amplify E. histolytica genes from extracted faecal DNA. Sensitivity and specificity are high (80%–100% and 100%, respectively). The advantage of molecular detection is that it is extremely sensitive (able to detect < 1 parasite) and reliably able to differentiate non-pathogenic Entamoeba species from E. histolytica. Drawbacks of this method are the high level of expertise required and the cost. The availability of the test is limited, but at our institution it has proved extremely valuable. Microscopy relies on identifying E. histolytica cysts and trophozoites.
For symptomatic intestinal infection and extraintestinal disease, treatment with metronidazole or tinidazole should be followed by treatment with iodoquinol or paromomycin. Most patients have a gradual illness onset days or weeks after infection. Symptoms include cramps, watery or bloody diarrhea, and weight loss.