Amoebiasis is caused by Entamoeba histolytica which leads to an intestinal infection causing severe diarrhoea.
Occurrence
Amebiasis occurs worldwide, but it is more common in areas of poor sanitation, particularly in the tropics. Most infections occur in Africa, Asia, and Central and South America.
Persons at high risk for severe disease include pregnant women, immunocompromised individuals, and patients receiving corticosteroids
Mode of Transmission
Faeco-oral route
Contamination of food by hands of unhygienic food-handler
Fresh vegetables polluted by sewage
Contaminated water
Incubation period
Incubation period: 2-4 weeks (sometimes months, occasionally even years).
During this period infected people will still excrete the cysts and can infect their surroundings.
Signs and Symptoms
- Abdominal (stomach) cramps
- Urgent, frequent, blood-stained stools
- Tenesmus (painful passage of stools)
- Foul smelling stools
- Slimy stools
- Fatigue and weight loss
Rarely, amoeba can enter the blood steam, causing:
- Fever
- Liver cysts
- Unexplained weight loss and/or illness
- Peritonitis (rarely)
- Diagnosis
- Stool analysis for ova/cysts.
Treatment
Antibiotic treatment prescribed by doctor (Metronidazole or Tinidazole)
Control and Prevention
- Educate the general public regarding personal hygiene - everyone should wash their hands before preparing/eating food and after defecation.
- It is important that everyone, particularly travellers to high risk areas, is informed regarding risks involved in eating unclean or uncooked fruits/vegetables and in drinking water of questionable purity.
- Known carriers should be treated.
- Chronic carriers should be taught about personal hygiene.
- Infected food handlers, etc., should stop working until 3 consecutive stool samples are negative. Screening of faeces of households and those exposed to the same source of infection is suggested.