Treatment of Amoebiasis

Diagnosis and Initial Assessment

Amoebiasis should be diagnosed through microscopic examination of fresh feces showing amebic trophozoites or after two different antibiotics for shigellosis have failed to produce clinical improvement, as recommended by the Centers for Disease Control and Prevention 1, 2
Indirect hemagglutination testing has over 90% sensitivity for amoebic liver abscess and should be performed in suspected cases, according to the Journal of Infection 3
Ultrasound should be performed in all patients with suspected amoebic liver abscess; consider CT scan if ultrasound is negative but clinical suspicion remains high, as suggested by the Journal of Infection 3

Metronidazole: 750 mg three times daily for 5-10 days for adults, as recommended by the Centers for Disease Control and Prevention 1, 2
Metronidazole: 30 mg/kg/day for 5-10 days for children, as recommended by the Centers for Disease Control and Prevention 1, 2
Same drug regimens as intestinal amoebiasis are used for amoebic liver abscess, according to the Journal of Infection 3
Most patients with amoebic liver abscess will respond within 72-96 hours of treatment initiation, as reported by the Journal of Infection 3

After completion of metronidazole or tinidazole treatment, all patients should receive a luminal amebicide to eliminate intestinal cysts and prevent relapse, as recommended by the Journal of Infection 3
Options for luminal amebicides include diloxanide furoate: 500 mg orally three times daily for 10 days, and paromomycin: 30 mg/kg/day orally in 3 divided doses for 10 days, according to the Journal of Infection 3

Surgical or percutaneous drainage of amoebic liver abscess is rarely required and should only be considered in cases of diagnostic uncertainty, persistent symptoms after 4 days of treatment, or risk of imminent rupture, as suggested by the Journal of Infection 3

Emphasize hand washing after using the bathroom and before preparing or eating food, as recommended by the Centers for Disease Control and Prevention 4
Avoid consuming untreated water or uncooked food in endemic areas, as recommended by the Centers for Disease Control and Prevention 1

If no improvement occurs within 2 days of treatment initiation, consider alternative diagnoses or drug resistance, as recommended by the Centers for Disease Control and Prevention 5

The Centers for Disease Control and Prevention, as reported by MMWR Recommendations and Reports, recommends not initiating treatment for amoebiasis unless microscopic examination of fresh feces demonstrates amebic trophozoites, or two different antibiotics for shigellosis have failed to produce clinical improvement 6

For patients with acute severe ulcerative colitis who have recent travel to endemic areas, the European Society of Gastrointestinal Endoscopy, as reported by Gut, suggests considering adding metronidazole pending stool microscopy if amoebiasis is suspected 7

The Centers for Disease Control and Prevention recommends that treatment should not be initiated unless microscopic examination of fresh feces demonstrates Entamoeba histolytica trophozoites, or two different antibiotics for shigellosis have failed after 4 days total 8
If dysentery is present but microscopy is unavailable or trophozoites are not definitively identified, the CDC suggests treating for shigellosis first with ampicillin or TMP-SMX before considering amoebiasis 8
Care must be taken to distinguish large white cells (nonspecific indicator of dysentery) from actual trophozoites, as amebic dysentery tends to be misdiagnosed, according to the CDC 8

The CDC warns that failure to provide a luminal agent after metronidazole/tinidazole therapy is the most common cause of relapse, and misdiagnosis between amebic and bacterial dysentery leads to inappropriate treatment 8