INTESTINALINTESTINAL AMOEBIASISAMOEBIASISan enteric diseasean enteric disease

Made and Presented by: Made and Presented by: Asiya FazalAsiya Fazal

ContentsContents IntroductionIntroduction Causative agentCausative agent EpidemiologyEpidemiology Mode of transmissionMode of transmission Clinical sign and symptomsClinical sign and symptoms Habitat of E.histolyticaHabitat of E.histolytica Life cycleLife cycle PathologyPathology DiagnosisDiagnosis TreatmentTreatment PreventionPrevention ReferencesReferences

Intestinal Intestinal AmoebiasisAmoebiasis

Intestinal Intestinal Amoebiasis,alsoAmoebiasis,also

called ‘’Amoebic called ‘’Amoebic DysenteryDysentery’’.’’.

It is a disease It is a disease characterizedcharacterized

by inflammation of by inflammation of thethe

intestines,particularly intestines,particularly the colon.the colon.

Best known species of amoeba that parasitizes human.

Global in its distribution,the incidence of infection exceeds 400 million cases

(W.H.O.)

First discovered in Russia in 1873 by Losch.

Causative agentCausative agent

The causative The causative agent of Intestinal agent of Intestinal

amoebiasis is the amoebiasis is the protozoan:protozoan:

“ “EntamoebaEntamoeba histolyticahistolytica””. .

Scientific meaningScientific meaning, , “ “Tissue dissolvingTissue dissolving””

Causative agentCausative agent

Morphologic forms:Morphologic forms:

E.histolyticaE.histolytica has has two formstwo forms..

1 - Cyst (infective 1 - Cyst (infective form)form)

2 - Trophozoite2 - Trophozoite

(active feeding form)(active feeding form)

EpidemiologyEpidemiology

10% world population is infected with 10% world population is infected with E.histolyticaE.histolytica (W.H.O) (W.H.O)

Amoebiasis is the third most common Amoebiasis is the third most common cause of death from parasitic disease. cause of death from parasitic disease. (next to malaria and schistosomes).(next to malaria and schistosomes).

In Pakistan approx.17% people become In Pakistan approx.17% people become infected with amoebic dysentery every infected with amoebic dysentery every year and the majority being children year and the majority being children (N.I.H).(N.I.H).

Mode of TransmissionMode of Transmission

Direct transmissionDirect transmission::With contaminated hands.With contaminated hands. Indirect transmissionIndirect transmission:: Contaminated food andContaminated food and

water.water. Other vital factorsOther vital factors::

Flies,vegetables,food Flies,vegetables,food handlers etc.handlers etc.

Clinical Clinical signs/symptomssigns/symptoms

Influenced by severity of infectionInfluenced by severity of infection Acute AmoebiosisAcute Amoebiosis : : Severe dysentery DehydrationSevere dysentery Dehydration (Anorexia)(Anorexia)

Blood & Mucus in faecesBlood & Mucus in faeces (Intense griping pain,frequently visits (Intense griping pain,frequently visits

latrines straining blood & mucus)latrines straining blood & mucus)

Prolapse of rectumProlapse of rectum

Clinical Clinical sign/symptomssign/symptoms

CHRONICamoebiasis

Abdominal pain

Diarrhea Or

Dysentery

Mucous withblood

In stool

Habitat of Habitat of E.histolyticaE.histolytica

E.histolytica inhibits E.histolytica inhibits large intestine.large intestine.

Trophozoite lives in Trophozoite lives in the intestinal lumen.the intestinal lumen.

May invade the May invade the mucosa, where they mucosa, where they feed on red blood feed on red blood cells and form ulcers.cells and form ulcers.

If intestinal motility If intestinal motility is rapid, amoeba is rapid, amoeba may be passed out may be passed out in liquid or in liquid or semisolid stool as semisolid stool as trophozoite.trophozoite.

If intestinal motility If intestinal motility is normal, amoeba is normal, amoeba will passed out as a will passed out as a resistant cyst.resistant cyst.

Life cycle of Life cycle of E.histolyticaE.histolytica

Quadrinucleated cystsQuadrinucleated cysts

(Infective stages)(Infective stages)

Contamination of food & HContamination of food & H22OO

Excystation in Small / large IntestineExcystation in Small / large Intestine

4 Metacyclic Forms (Amoebules)4 Metacyclic Forms (Amoebules)

Amoebules in Intestinal lumenAmoebules in Intestinal lumen

Binary Fission 8 Amoebae Binary Fission 8 Amoebae

Invade intestinal tissues (Trophozoites)Invade intestinal tissues (Trophozoites)

Asexual reproduction by binary fissionAsexual reproduction by binary fission

(Colonies of Amoebae: Increase in (Colonies of Amoebae: Increase in Population)Population)

Asexual reproduction by binary fissionAsexual reproduction by binary fission

(Increase in Population)(Increase in Population)

Last generation before encystment:Precystic Last generation before encystment:Precystic stagestage

Trophozoites Round up, Expel food Trophozoites Round up, Expel food particlesparticles

Encystment & Cysts in lumenEncystment & Cysts in lumen

Cysts in faeces Environmental Cysts in faeces Environmental

contaminationcontamination

PathologyPathology

Invasion of large Invasion of large intestine by the intestine by the action of enzymes:action of enzymes:

CysteinCystein Protease.Protease.

Becomes site of Becomes site of secondary infection secondary infection for certain bacteria for certain bacteria and viruses.and viruses.

PathologyPathology

Invasion of Intestinal mucosaInvasion of Intestinal mucosa

Multiply asexually: Binary fissionMultiply asexually: Binary fission

Invasion in deeper layers (Sub Invasion in deeper layers (Sub mucosa)mucosa)

Spread laterally Spread laterally

Flask shaped ulcers:Caecum & Ascending Flask shaped ulcers:Caecum & Ascending ColonColon

PathogenesisPathogenesis

DiagnosisDiagnosis

Diagnosis

Stool microscopy Serology Sigmoidoscopy

TreatmentsTreatments

Iodoquinol650mg

20 days

Iodoquinol650mg

20 days

Diloxanide furoate500mg

10 days

Diloxanide furoate500mg

10 days

Paromomycin500mg

10 days

Paromomycin500mg

10 days

Tinidazole2g

3 days

Tinidazole2g

3 days

Metronidazole500mg-750mg

5-10 days

Metronidazole500mg-750mg

5-10 days

TreatmentsTreatments

PreventionPrevention

Wash hands with soap & water at least 10 Wash hands with soap & water at least 10 seconds after using toilet.seconds after using toilet.

Clean bathroom & toilets often.Clean bathroom & toilets often. Avoid sharing towels.Avoid sharing towels.

Avoid eating raw vegetables.Avoid eating raw vegetables. Boil water or treat with iodine tablets.Boil water or treat with iodine tablets.

Health education and personal hygiene.Health education and personal hygiene.

ReferencesReferences

www.wikipedia.com www.sciencedirect.com Foundations of parasitology.Foundations of parasitology.