Entamoeba Histolytica

1
Entamoeba Histolytica

• The Beast of the Bowels

2
Profile of the Pathogen

• Entamoeba Histolytica is a unicellular amoeba
  that infects humans and lives in the lower
  bowels.
• Its name means bowel destroying amoeba.
• It infects an estimated 50 million people
  worldwide
• It is the third leading cause of parasitic
  death, surpassed only by schistosomiasis and
  malaria.

3
Microorganism of Malice

• The 4 stages of Entamoeba Histolyticas life
  are the trophozoite form, the precyst form, the
  cyst form and the metacyst form.

4
Protist of Perniciousness

• Measures between 15 and 50 micrometers.
• Reproduces primarily by binary fission
• Has hyaline ectoplasm and distinct karyosome
  in a nucleus.
• Adheres to intestinal wall via lectin an
  adherence lectin
• Consumes erythrocytes and other somatic
  cells
• Is capable of lysing leukocytes and evading
  complement-mediated lysis

5
The Cyst of Corruption

• In the precyst form, the cell shrinks as it
  extrudes food vacuoles
• The cyst forms 4 distinct nuclei, measures
  between 10 and 20 micrometers, and has no visible
  chromatoid bodies.
• The metacyst is a tetranucleated amoebae
  without a shell around it.

6
The Circle of Calamity

• The cyst forms in the bowels, and from there
  is passed out to the environment inside fecal
  matter.
• From the environment, the cysts are ingested
  by another human host.

7
Suffering Spreads

• Entamoeba Histolytica is transmitted by the
  fecal-oral route.
• Incidence of Entamoeba Histolytica is high
  in developing countries with poor sewage.
• The only population that shows increased
  incidence of Entamoeba Histolytica infection in
  the industrialized world is that of homosexual
  men.

8
The Reaping

• Infection with Entamoeba Histolytica is known
  as amebiasis
• There are 2 forms of amebiasis, invasive and
  non-invasive

9
The Battlefield
10
The Lurking Darkness

• Non-invasive amebiasis accounts for 90 of
  Entamoeba Histolytica infections
• The symptoms include slight stomach pain and
  infrequent non-dysenteric diarrhea

11
Eviscerator of Viscera

• Entamoeba Histolytica trophozoites
  penetrate the mucosa and begin to feed on the
  epithelial intestinal surface
• This feeding causes characteristic
  flask-shaped ulcers of necrotic tissue in the
  intestines
• Small ulcers grow and meet with other ulcers
  to cause sloughing of the intestinal wall
• Sometimes the intestinal skin around the
  ulcer thickens, creating an ameboma

12
Torment of the Transgressor

• The primary symptom is dysentery, with
  affected individuals sometimes suffering upwards
  of 20 bowel movements a day
• Stool is soft, and may contain blood, mucus
  or pieces of intestinal epithelium
• In some cases gangrene sets in within the
  intestines, or the intestines will rupture
  causing peritonitis

13
The Abomination of the Abdominal Cavity

• Occasionally Entamoeba Histolytica will
  spread to other organs.
• The most common one is the liver, which it
  reaches through the hepatic portal vein.
• In the liver it causes abscesses,
  hepatomegaly and cirhosis.
• Even more rarely, Entamoeba Histolytica may
  spread to other parts of the body such as the
  lungs or brain.

14
Bring out your dead

• Mortality rate in patients with
  uncomplicated amebic liver abscess is less than
  1
• Fulminant amebic colitis has a mortality
  rate of more than 50
• Pleuropulmonary amebiasis has a mortality
  rate of 15-20 ?
• Amebic pericarditis has a case fatality rate
  of 40
• Cerebral amebiasis is highly fatal, with a
  90 death rate