1. Amebiasis
(Amebic Dysentery)

2. Amebic Dysentery
Causal agent: Entamoeba histolytica is well recognized as a pathogenic amoeba.
History: Loosh was first described in 1875
Geographic Distribution: Worldwide, with higher incidence of amebiasis in developing countries. 
In industrialized countries, risk groups include male
homosexuals, travelers and recent immigrants, and
institutionalized populations.

3. Morphology Different form of E. histolytica; a- trophozoite b- precyst
c- cyst(1, 2, 4 nuclei)

4. Entamoeba histolytica trophozoite

5. Entamoeba histolytica immature cyst

6. Entamoeba histolytica mature cyst

7. Life cycle of E. histolytica

8. Transmission 1-driect contact of person to person( fecal-oral)
2- Veneral transmission among homosexual
males
3- Food or drink contaminated with feces
containing the E.his. cyst
4- Use of human feces for soil
fertilizer
5- contamination of foodstuffs by flies, and
possibly cockroaches

9. Pathogenesis Depends on: Parasite virulence. Host resistance.
Condition of the intestinal tract.
Pathogenic agent: trophozoites invade intestinal mucosa.
Trophozoites produce histolytic enzyme that produce necrosis of mucosa leading to the formation of flask-shaped ulcer.

10. Pathogenesis & Complications

11. flask-shaped ulcer

12. This is followed by: Proliferation of connective tissue.
Brain abscess
Proliferation of connective tissue.
Intensive ulcerations.
Extra-intestinal invasion to brain, liver, lung or skin.
Lung abscess
Skin abscess
Liver abscess
(common)
Blood vessel

13. Diagnosis (Intestinal amoebiasis)
Clinically: Dysentery: painful frequent evacuation of small quantities of stool containing mucus tinged with blood.
Laboratory:
1- Direct stool examination: Trophozoites are found in diarrhoeic stool. Cysts are found in formed stool.
- Wet preparation.
- Iodine stained.
- Permanent stain with iron haematoxylin or
trichrome.
2- Concentration techniques for cysts.

14. Serological tests in chronic amoebiasis.
3- Indirect diagnosis:
Serological tests in chronic amoebiasis.
Detection of copro-antigen using monoclonal antibodies.
Molecular techniques.
Radiological examination:
using barium enema.
wash
wash
wash
Coating the well with MAb and add patient’s stool to detect Entamoeba Ag

15. Treatment of Amoebic abscesses by aspiration or open surgical drainage
Metronidazole, Tinidazole.
Very effective in killing amoebas in the wall of the intestine, in blood and in liver abscesses.
Diluxanide furoate.
kills trophozoites and cysts in the lumen of the intestine.
Tissue amoebicide
Luminal amoebicide
Treatment of Amoebic abscesses by aspiration or open surgical drainage

16. Treatment of Amoebic abscesses by aspiration or open surgical drainage
Surgical drainage of abscess
Thick chocolate-coloured or pus with trophozoites
Aspiration of
abscess

17. Epidemiology Control Cyst passers are the main source of infection.
Cysts remain viable in faeces for few days, in water for longer periods.
Cysts are killed by dryness, heat (over 55ºC) and by chlorine.
Control
Treatment of patients.
Examination and treatment of food handlers.
Environmental sanitation.
Personal prophylaxis.
Human faeces should not be used as fertilizers.