Amoebiasis

Amoebiasis

A common parasitic infection of the gastrointestinal system acquired through oral−faecal transmission

Causes

• The protozoan Entamoeba histolytica

Clinical features

It may present as: Amoebic dysentery

• Persistent mucoid/bloody diarrhoea

• Abdominal pain

• Fever/chills

  Amoebic abscess which can occur in one of the following forms as a result of spread via the blood   

  stream:

• liver abscess − swelling/pain in the right sub−costal area

• brain − presenting as space−occupying lesion

• lungs − cough and blood stained sputum

• amoeboma − swelling anywhere in the abdomen

• anal ulceration − may occur by direct extension from the intestinal infection

• chronic carriers − symptomless

Differential diagnosis

• Bacillary dysentery

• Any other cause of bloody diarrhoea

• Cancer of the liver

• Other causes of swelling in the liver

Investigations

Stool: microscopy for cysts and motile organisms

Management

Correct any dehydration

metronidazole 800mg every 8 hrs for 8−10 days

child: 10mg/kg per dose

or tinidazole 2g daily for 3 days

Chronic carriers (luminal) and tissue amoebiasis (liver, lung, brain, amoeboma)

metronidazole 400mg every 8 hours for 10 days

child: 10mg/kg per dose

or tinidazole 2g daily for 5 days

child: 50mg/kg per dose

Notes

metronidazole, tinidazole: contraindicated in pregnancy; avoid alcohol during treatment

and for 48 hours after

metronidazole: take after food

Prevention

• Educate the public on personal and food hygiene (washing hands before eating), proper

faecal disposal

• Ensure proper management of carriers

• Promote use of clean drinking water