Amoebiasis due to Entamoeba histolytica

What it is

From: Orphanet

A parasitic disease caused by the protozoa, Entamoeba histolytica, mainly occurring in tropical regions after the ingestion of an amoebic cyst, and resulting in clinical manifestations that may range from an asymptomatic state to amoebic colitis (violent abdominal pain, a painful contracted feeling around the anal sphincter, blood and mucus in the stools but without the presence of fever), or amoebic liver abscesses (fever, chills, abdominal pain, weight loss, hepatomegaly) that can be fatal if not immediately treated. Extraintestinal involvement elsewhere (i.e. thoracic, hepatic) is extremely rare.

Reported clinical features and what the terms mean

The following findings are associated with this condition in Orphanet. They are not a checklist for diagnosing yourself, and they do not all occur in every affected person. Some are examination, imaging or laboratory findings that cannot be recognised at home.

The frequency labels describe how often a finding was reported among people with the condition in the source. They do not give the chance that a person with that symptom has the condition. Definitions below reproduce HPO terminology; they explain the term, not the likely severity in an individual.

Abdominal pain · Occasional (29-5%)

An unpleasant sensation characterized by physical discomfort (such as pricking, throbbing, or aching) and perceived to originate in the abdomen.

Bloody diarrhea · Occasional (29-5%)

Passage of many stools containing blood.

Chest pain · Occasional (29-5%)

An unpleasant sensation characterized by physical discomfort (such as pricking, throbbing, or aching) localized to the chest.

Diarrhea · Occasional (29-5%)

Abnormally increased frequency (usually defined as three or more) loose or watery bowel movements a day.

Gastrointestinal dysmotility · Occasional (29-5%)

Abnormal intestinal contractions, such as spasms and intestinal paralysis, related to the loss of the ability of the gut to coordinate muscular activity because of endogenous or exogenous causes.

Weight loss · Occasional (29-5%)

Reduction of total body weight.

Protracted diarrhea · Occasional (29-5%)

Abnormal pericardium morphology · Very rare (<4-1%)

An abnormality of the pericardium, i.e., of the fluid filled sac that surrounds the heart and the proximal ends of the aorta, vena cava, and the pulmonary artery.

Abnormal sputum · Very rare (<4-1%)

Abnormal appearance of material expectorated (coughed up) from the respiratory system and that is composed of mucus but may contain other substances such as pus, blood, microorganisms, and fibrin.

Acute colitis · Very rare (<4-1%)

An acute and self-limited inflammatory disease of the large intestine (colon, cecum and rectum).

Anemia · Very rare (<4-1%)

A reduction in erythrocytes volume or hemoglobin concentration.

Congestive heart failure · Very rare (<4-1%)

The presence of an abnormality of cardiac function that is responsible for the failure of the heart to pump blood at a rate that is commensurate with the needs of the tissues or a state in which abnormally elevated filling pressures are required for the heart to do so. Heart failure is frequently related to a defect in myocardial contraction.

Constrictive pericarditis · Very rare (<4-1%)

Presence of a thickened, fibrotic pericardium that forms a non-compliant shell around the heart, and resulting from chronic inflammation of the pericardium.

Cough · Very rare (<4-1%)

A sudden, audible expulsion of air from the lungs through a partially closed glottis, preceded by inhalation.

Other findings in the same source

From: Orphanet

Additional reported features include Deep venous thrombosis (Very rare (<4-1%)); Dyspnea (Very rare (<4-1%)); Elevated circulating alkaline phosphatase concentration (Very rare (<4-1%)); Elevated circulating hepatic transaminase concentration (Very rare (<4-1%)); Fever (Very rare (<4-1%)); Hemoptysis (Very rare (<4-1%)); Hypoalbuminemia (Very rare (<4-1%)); Increased total leukocyte count (Very rare (<4-1%)); Intestinal obstruction (Very rare (<4-1%)); Liver abscess (Very rare (<4-1%)). This is a selected summary, not a complete description of the condition.

When it may begin

From: Orphanet

All ages

Inheritance in the source

From: Orphanet

Not applicable

Which doctor should you see?

The suggested department for discussing Amoebiasis due to Entamoeba histolytica is Infectious Diseases, with a general physician / infectious disease specialist as the relevant type of clinician. General physician / Family Medicine; paediatrician for children. Referral depends on symptoms.

This is an editorial referral starting point. The appropriate clinic depends on the person’s age, symptoms, previous diagnosis and local services. The first clinician can decide whether another specialty or a team is needed; a department label does not confirm the diagnosis.

How to prepare for an assessment

Bring a short timeline of the main symptoms: when they first appeared, whether they are constant or episodic, what seems to change them, and how they affect daily activities. Include previous reports, discharge summaries, current medicines and supplements, allergies, and any relevant family history. A dated record is more useful than trying to match every feature in an online article.

Ask the clinician what is already established and what remains uncertain. If a test is suggested, ask what question it answers, what its limitations are and how the result would change the next step. The information here is not an instruction to arrange every possible test. In children, bring growth, developmental and school information if it is relevant to the concern.

• Which exposure or organism is suspected, and what evidence would confirm it?
• Are precautions, vaccination or advice for close contacts relevant to this infection?
• What should happen if symptoms worsen or do not improve as expected?

Treatment discussions and follow-up

Where the source describes treatments, these are an overview of possible care, not a prescription for an individual. Ask which option applies to the confirmed diagnosis, what benefit is expected, what adverse effects to watch for and how progress will be assessed. Availability, approvals and local practice can differ from the country described in the source.

Before leaving the appointment, clarify the next review date, who will communicate results, and whom to contact if the situation changes. Discuss difficulties with sleep, work, school, mobility, eating or emotional wellbeing when these are relevant. Practical support may require coordination between the treating clinician and other services.

The collected references do not establish a complete prevention or long-term outlook section for this entry. Missing information should not be interpreted as proof that prevention is impossible or that a particular outcome is inevitable. Ask what is known for the exact subtype, stage and personal circumstances, and which uncertainties remain.

When to seek emergency help

Severe breathing difficulty, collapse, new stroke-like symptoms, a seizure that is prolonged or repeated without recovery, uncontrolled major bleeding, or an immediate risk of self-harm require emergency help. In India, call 112 or reach the nearest emergency department. This is a general, non-exhaustive warning list; it is not a condition-specific triage tool.