Amoebiasis
Investigations
● Fresh stool sample: may reveal motile trophozoites on microscopy.
● Sigmoidoscopy: typical flask-shaped ulcers may be seen and should be scraped for microscopy.
● Antibodies: detectable by immunofluorescence in 95% of patients with hepatic amoebiasis and intestinal amoeboma but in only ~60% of dysenteric amoebiasis.
● PCR: also sensitive but not widely available.
If the clinical picture suggests amoebic abscess, there may be a neutrophil leucocytosis and a raised right hemidiaphragm on CXR.
Confirmation is by liver USS.
Management
Intestinal and early hepatic amoebiasis responds quickly to oral metronidazole. Diloxanide furoate should be given orally for 10 days after treatment to eliminate luminal cysts. Drainage/aspiration may be required for amoebic abscess to prevent rupture; this yields characteristic brown ‘anchovy sauce’ liquid. Surgical drainage is needed if rupture occurs.
Acute amoebic dysentery
Metronidazole 800 mg thrice daily for 5 days. (child 50mg/kg/day in 3 divided doses) or
Tab Tinidazole 2mg/day for 5 days. or
Tab Secnidazole 2 g as single dose. or
Tab Ornidazole 500mg BD for 5 days. or
Diloxanide furoate 500 mg plus Metronidazole 400 mg TDS for 5 days. or
Tinidazole 1000 mg at bed time for 3 days.
if abdominal pain: Tab.Buscopan PO BD.
if severe colic : Inj Buscopan 2 ml IM
if stool shows pus cells: Cap Tetracycline 500mg PO QID 10 days.
if dehydation: IVF DNS
Chronic Amoebic Dysentery (asymptomatic cyst passers):
Tab Diodoquin 250mg PO TDS or
Tab Furamide 500 mg PO TDS or
Tab Dependal - M PO TDS.
Amoebic Liver Abscess:
Inj Metrogyl (200 mg/5ml) 400 ml IV OD 10 days
after 10 days - Tab Diloxanide 500 mg PO TDS for 10 days.
Drainage by needle aspiration if:-
Abscess points towards epigastrium or right hypochondrium.
Significant elevation of right dome of diaphragm.
Fever or hepatomegaly persists after 10 days of antiamoebic treatment.
Persistent localized tenderness.
'cold' area demonstrated by hepatic scan.