Differences Between Amoebic Dysentery and Bacillary Dysentery

Dysentry is an infective disease of the large bowels characterized by frequent passing of blood and mucus with stool along with several abdominal cramps. Various microbial and chemical causes can result into dysentery in humans.
Among the microbial aetiology are included both protozoa and bacteria. Dysentery caused by protozoa is called amoebic dysentery and dysentry caused by bacteria is called bacillary dysentery.

Both amoebic and bacillary dysentery resemble each other, but can be differentiated on aetiological, clinical and laboratory grounds. Followings are the differences between amoebic dysentery and bacillary dysentery :

Differences in Pathology

Features Amoebic Dysentery Bacillary Dysentery
Causative agent Entomoeba histolytica Shigella species, Enterohemorrhagic E. coli, Vibrio parahemolyticus, Campylobacter jejuni
Nature of lesion Necrotic due to proteolytic ferment Suppurative due to diffusible toxins
Depth of ulcer Usually deep Shallow
Margin of ulcer Ragged and undermined Uniform, clear-cut (sharp)
Intervening mucos Normal Inflamed
Type of necrosis (cellular level) Pyknotic (pyknotic body and mouse eaten cells) Karyolysis (ghost cell and ring nucleus)
Liver abscess Common Rare
Cellular response Mononuclear Polymorphonuclear

Differences in Clinical Features

Features Amoebic Dysentery Bacillary Dysentery
Onset Slow Acute
Fever Absent Present
Abdominal tenderness Localized Generalized
Tenesmus Absent Present

Differences in Macroscopic Features of Stool

Features Amoebic Dysentery Bacillary Dysentery
Number 6-8 motions per day Over 10 motions per day
Amount Relatively copious Small
Odor Offensive Odorless
Color Dark red Bright red
Nature Blood and mucus mixed with feces Blood and mucus, no feces
Reaction Acidic Alkaline

Differences in Microscopic Features of Stool

Features Amoebic Dysentery Bacillary Dysentery
Cellularity Poor High
RBC In clumps, reddish yellow in color Discrete or in rouleaux, bright red in color
Pus cells Scanty Numerous
Macrophages Very few Large and numerous, many of them contain RBCs, hence mistaken for E. histolytica
Eosinophils Present Scarce
Pyknotic bodies Very common Nil
Ghost cell Nil Numerous
Parasites Trophozoites of E. histolytica Nil
Bacteria Many, motile Scanty, non-motile
Charcot-leyden crystals Present Nil

5 Responses

  1. Great. Awsomelly interesting. Thanks very much. Coming back to what you said at the level of ” DIFFERENCE IN PATHOLOGY ” : cellular response; does it mean that in amoebic dysentery polymorphonuclear are absent? I remember the once said eosinophiles ( a polymorphonuclear cell ) fights against parasitic infections and is from them that Charcot Leyden crystal originates. Mononuclear such as macrophages and lymphocytes are mostly present in bacillary infections. so, I think level…………………. To be corrected. To confirm what I am saying, go to DIFFERENCES IN MICROSCOPIC FEATURES YOU WROTE.

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