Clinical features: Amoebiasis is caused by the protozoan parasite Entamoeba histolytica. It is usually transmitted from person to person through feacal contamination of food or hands, but may also be transmitted via sexual contact in homosexual men. Amoebic dysentery occurs when the parasites invade the intestinal wall and abscesses may develop in the liver or, less frequently, in the lung or brain as a result of hematogenous spread. Skin lesions may also occur. Pregnant women and individuals who are malnourished or immunocompromised are most vulnerable to systemic infection.
Treatment guidelines
Intestinal amoebiasis |
|
Drug of choice |
Metronidazole (O) 200 mg/250 mg |
Adult |
750-800 mg eight hourly with food for 5 days |
Children |
10 mg/kg weight per day |
Indicative |
|
1 - 3 years |
200-250 mg eight hourly for 5 days. |
3 - 7 years |
200-250 mg six hourly for 5 days. |
7 - 10 years |
400-500 mg eight hourly for 5 days. |
Above 10 years as for adult |
|
Second choice |
Tinidazole (O) |
Adult |
2 gm daily for 3 consecutive days as a single dose for three days. |
Children |
50 mg/kg body weight daily for 3 days. |
Amoebic liver abscesses |
|
Drug of choice |
Metronidazole (O) |
Adult |
400-500 mg eight hourly for 10 days. Repeat course after 2 weeks if necessary. |
Children |
|
1 - 3 years |
100-200 mg eight hourly for 10 days. |
3 - 7 years |
100-200 mg six hourly, for 10 days. |
7 - 10 years |
200-400 mg eight hourly, for 10 days. |
NOTE: Metronidazole should be taken with food. The course may be repeated after two weeks if necessary. |
Aspiration of the abscess may be necessary where it is suspected that it may rupture. Always consider the possibility of a pyogenic abscess.
|
CAUTION
• Patients on metronidazole should not take alcohol.
• Metronidazole is contraindicated in early pregnancy.
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