Synonym(s)
Amoeba dysentery; invasive intestinal amebiasis
DefinitionThis section has been translated automatically.
Intestinal infection with the protozoon Entamoeba histolytica.
ClassificationThis section has been translated automatically.
Entamoeba histolytica.
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Occurrence/EpidemiologyThis section has been translated automatically.
- Worldwide prevalence: about 50 million people worldwide contract invasive amoebiasis annually, up to 100,000 deaths annually (WHO, 1997).
- Occurrence: mainly in warm countries with low hygienic standards, autochthonous infections in temperate zones very rare (e.g. sewage workers), occurrence in male homosexuals (oral-anal contact, rectal lavage).
EtiopathogenesisThis section has been translated automatically.
Faecal-oral uptake of cysts with contaminated food; release of smaller, vegetative forms, so-called minuta forms (trophozoites) from cysts in the intestine. Trophozoites multiply by bifurcation and form cysts which are excreted with the stool in a mature, quadrenuclear state. When trophozoites penetrate the intestinal wall and phagocytise erythrocytes, they become so-called magnaforms.
Clinical featuresThis section has been translated automatically.
- Colon: after invasion of trophozoites into the mucosa, undermined ulcerations, so-called bottleneck or canteen ulcers, develop that reach down to the submucosa.
- Abdominal pain, fever, "raspberry-jelly", slimy-bloody diarrhoea, milder forms: mushy-watery diarrhoea (more frequent), ulcers reaching the submucosa (so-called bottleneck or canteen ulcers), gradual development over several weeks to years. Chronic courses are possible.
- Perforation
- Toxic Megacolon
- Amoeboma.
DiagnosisThis section has been translated automatically.
- In the chair:
- Stool culture (to exclude simultaneous bacterial infections)
- Stool microscopy (sensitivity of 70%): MIFC method in stool (preferably in native stool, fresh stool/mucus flake [in 3 stool samples]): Microscopic detection of cysts, minota forms and magnaforms in stool. Pathogenic and apathogenic forms of intestinal lumen cannot be differentiated, characteristics of cysts: E. histolytica larger than 10 µm, E. histolytica maximum 4 nuclei. Detection of magnaforms is proven by amoebic colitis.
- Antigen detection (ELISA, sensitivity comparable with microscopy)
- PCR (highest sensitivity)
- In serum (indication of invasion):
- Serum antibodies (ELISA)
- Transaminases, cholestasis parameters
- Inflammation parameters
- Blood count
- Electrolytes.
- Imaging (abscess, perforation, toxic megacolon):
- Abdominal sonography
- Computer tomography
- Colonoscopy.
Differential diagnosisThis section has been translated automatically.
- Diseases that may be associated with similar clinic:
- Diarrhoea induced by bacterial toxins
- Shigellose
- Salmonellosis
- Campylobacter infection
- Yersiniosis
- Chronic inflammatory intestinal diseases
- Malignant tumors.
Complication(s)This section has been translated automatically.
- Perforation with peritonitis
- Toxic megacolon
- Amoeboma.
TherapyThis section has been translated automatically.
- Standard: Metronidazole 3 times/day 10 mg/kg bw (max. 3 times/day 800 mg) i.v. or orally over 10 days (dosage for adults and children).
- In mild cases: Tinidazole 2 g/day orally for 5 days (children: 30 mg/kg bw/day, maximum 2 g/day). Tinidazole is no longer approved in Germany, but is available from pharmacies abroad ( off-label use).
- Subsequently cyst treatment: Paromomycin 3 times/day 500 mg/day p.o. for 9-10 days (children: 10 mg/kg bw/day).
- Alternatively: Diloxanidfuroat, Nimorazol, Chloroquin.
- In pregnant women: treatment indicated (however, 5-nitroimidazole should not be given in the 1st trimester).
ProphylaxisThis section has been translated automatically.
- Food hygiene (ice cubes, salads, ice cream, open juices)
- Avoid oral-anal sexual contacts and rectal lavage.
AftercareThis section has been translated automatically.
- Control of the success of therapy: in severe cases: blood count, liver values, cholestasis and inflammation parameters during and after treatment, time intervals according to the severity of the disease.
- Stool examination: 6 weeks after the end of treatment.
Note(s)This section has been translated automatically.
Current therapy recommendations can be found in the AWMF guidelines.
LiteratureThis section has been translated automatically.
- Annesley J (1828) Researches into the causes, nature and treatment of the more prevalent diseases of warm climates generally. Longman, Rees, Orme, Brown and Green, London, Vol. 2 p. 247
- Budd G (1857) On diseases of the liver. Churchill, London, United Kingdom
- Burchard GD et al (2003) Therapy of tropical diseases after returning from travel. Internist 44: 633-642
- Kucik CJ et al (2004) Common intestinal parasites. On Fam Physician 69: 1161-1168
- Losch FA (1975) Massive development of amebas in the large intestine. Translation from the original in Russian. Am J Trop Med Hyg 24: 383-392
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Amebiasis;Disclaimer
Please ask your physician for a reliable diagnosis. This website is only meant as a reference.
Prof. Dr. med. Peter Altmeyer