DIAGNOSIS OF INTESTINAL AMOEBIASIS

STOOL EXAMINATION

MACROSCOPIC EXAMINATION

• Foul smelling, copious and semiliquid.

• Brownish black in colour.

• Intermingled with blood and mucus.

• Not adhere to container.

MICROSCOPIC APPEARANCE

• Cellular exudate scanty.

• Nuclear masses of pus cells, epithelial cells and

macrophages.

• RBCs in clumps with yellow or brown red colour.

• Charcot-Leyden crystals-diamond shaped clear refractile

crystals.

Actively motile trophozoites in fresh stools.

Presence of ingested RBCs

Nucleus not visible.

Cyst has smooth, thin cell wall

Contains round refractile chromatoid bars.

IODINE STAINED PREPARATION• Demonstration of cysts and trophozoites.

• Stains yellow to light brown.

• Nucleus clearly visible with central karyosome.

• Cytoplasm smooth and hyaline appearance.

• Nuclear chromatin- Bright yellow

Glycogen-Golden brown

• Chromatoids-No staining

TRICHROME STAIN is also used to demonstrate trophozoites and cysts.

Microscopy

AB

MUCOSAL SCRAPING

• Scrapings obtained by sigmoidoscopy is examined

• Include:

• Wet mount and iron hemotoxylin and

immunofluoroscent staining.

STOOL CULTURE

Sensitive method in diagnosing chronic and asymptomatic intestinal amoebiasis

Medias used are:

Boeck and Drbohlav media.

NIH polygenic media.

Craig’s medium

Nelson’s medium.

Robinson’s medium

SERODIAGNOSIS

Indirect haemoagglutination(IHA)

Latex agglutination test

ELISA

Positive only in invasive

amoebiasis

MOLECULAR DIAGNOSIS

DNA probes

Radioimmunoassay

It is rapid and specific method

Intestinal Amoebiasis

Stool Examination

1.Microscopy

2.Macroscopy

3. Iodine stained

preperation

4.Trichrome stained

preparation

Stool Culture

Media used:

1.Boeck and Drbohlav

2.NIH polygenic

3.Craig’s

4.Nelson’s

5.Robinson’s

Mucosal Scraping

1. Wet mount stained

preparation

Serodiagnosis

1.IHA

2.ELISA

3.Latex Agglutination test

Molecular diagnosis

DNA probe

DIAGNOSIS OF EXTRAINTESTINAL AMOEBIASIS

MICROSCOPY

• Pus aspirated from liver abscess- demonstrate trophozoites of E.histolytica in less than 20% cases.

• Aspirate from the margin of the abscess show trophozoites.

• Cysts are never seen in extraintestinal amoebiasis.

LIVER BIOPSY

• Trozpozoites of Entamoeba histolytica may be seen in

liver biopsy specimen in case of hepatic amoebiasis or

amoebic hepatitis.

SEROLOGICAL TESTSIt has immense value in diagnosis of hepatic amoebiasis.

1) Complement fixation testing

2) Indirect hemoagglutination(IHA)

3) Latex agglutination

4) Countercurrent immunoelectrophoresis(CIE)

5) Gel diffusion precipitation(GDP)

6) Cellulose acetate membrane precipitation(CAP)

7) ELISA

RADIOLOGICAL EXAMINATION

Radioisotope scan of liver may locate space occupying

lesions.

USG, CT or MRI also found useful in detection of

amoebic liver abscess

AMOEBIC LIVER ABSCESS

Microscopy

Of pus or aspirate

Histopathologicalexamination

Of pus or aspirate

Serodiagnosis

1.IHA

2.ELISA

3.Latex Agglutination

Radiological Examination

1.X-ray

2.USG

3.CT Scan

4. MRI

Stool Examination

TREATMENT

3 classes of drugs:

1) Luminal Amoebicides

2) Tissue amoebicides

3) Both luminal and tissue amoebicides

LUMINAL AMOEBICIDES

Diloxanide Furoate

Paromomicin

Iodoquinol

Tetracycline-Act only in intestinal lumen not in tissues.

TISSUE AMOEBICIDE Emetine

Chloroquine

Effective in systemic infection

Less effective in intestine

Dosage of chloroquine in amoebic liver abscess is 1 g for 2 days followed by 5 g daiily for 3 weeks.

BOTH LUMINAL AND TISSUE AMOEBICIDE

Metronidazole

Tinidazole

Ornidazole

Act on both sites

These are the drugs of choice for amoebic colitis and amoebic liver abscess.

Asymptomatic E.histolytica should be treated.

Oral rehydration and electrolyte replacement should

be done whenever necessary.

PROPHYLAXIS

Generally for all fecal oral infection

Food and water have to be protected from

contamination with excreta.

Detection and treatment of carriers.

Health education