Amoebiasis is a parasitic infection caused by intestinal protozoan Entamoeba histolytica. The transmission is fecal-oral (hands, water and food contaminated with feces containing amoebic cysts). Usually, ingested cysts release in the intestine of non-pathogenic amoebae and 90% of carriers are asymptomatic.
In a small number of people infected, pathogenic amoebae penetrate the mucous
colon: the intestinal form of amoebiasis or amoebic dysentery. The clinical picture is similar to that of shigellosis, which is the main cause of dysentery.
Occasionally, the pathogenic amoebae migrate through the bloodstream and form abscesses. The extraintestinal the most common form of amoebiasis is amoebic liver abscess.
Clinical signs:
– Amoebic dysentery
• diarrhea with mucus and blood red
• abdominal pain, tenesmus
• no fever or moderate fever
• Possible signs of dehydration
– Amebic liver abscess
• painful hepatomegaly; sometimes jaundice
• anorexia, nausea, vomiting, weight loss
• intermittent fever, sweating, chills night; poor general condition
Laboratory:
– Amoebic dysentery: evidence of mobile trophozoites (E. histolytica histolytica) in fresh stool
– Amoebic liver abscess: indirect hemagglutination test and ELISA
Treatment:
– Amoebic dysentery
• The presence of cysts alone should not lead to the treatment of amoebiasis.
• In case of intestinal amoebiasis confirmed:
tinidazole PO
Children: 50 mg / kg / day once daily for 3 days (without exceeding 2 g / day)
Adult: 2 g / once daily for 3 days or metronidazole PO
Children: 45 mg / kg / day in 3 divided doses for 5 days
Adult: 1.5 g / day in 3 divided doses for 5 days
• In the absence of laboratory, the first-line treatment for dysentery is for shigellosis (see page 86). Treat amoebiasis in case of failure of treatment of shigellosis well conducted.
• Oral rehydration salts (ORS) if risk or dehydration (follow the WHO protocols, pages 306-311).
– Amebic liver abscess
• tinidazole PO: same treatment for 5 days
• metronidazole PO: same treatment for 5 to 10 days.
