Difference Between Amoebic Dysentery And Bacillary Dysentery


Amoebic Dysentery

Amoebic dysentery also referred to as Amebiasis is an infectious disease caused by a protozoan parasite referred to as Entamoeba histolytica, which causes both intestinal and extraintestinal infections. Some of the risk factors for amebiasis include consuming contaminated food or water, association with food handlers, whose hands are contaminated, fertilizer made of human waste, being pregnant and contact with contaminated medical devices such as colonic irrigation devices.

Amebiasis occurs worldwide, however it is most common in tropical areas that have crowded living conditions and poor sanitation. Africa, Mexico, parts of South America and India have major prevalence of amebiasis.

Common Symptoms

Only about 10-20% of infected individuals show symptoms and signs. The symptoms and signs include:

  • Fatigue
  • Fever and chills
  • Weight loss
  • Flatulence
  • Intermittent constipation
  • Loose stool
  • Mild abdominal cramping
  • Frequent watery or bloody stools with severe abdominal cramping
  • Appetite loss

Bacillary Dysentery

Bacillary dysentery is an intestinal infection caused by a group of Shigella bacteria which can be found in the human gut. Bacillary dysentery is transmitted directly by physical contact with the faecal material of a patient or carrier including (during sexual contact) or indirectly through consumption of contaminated food and water.

Infection by Shigella may be asymptomatic or only cause mild illness. For patients who develop bacillary dysentery, symptoms may include:

  • Acute onset of fever
  • Diarrhea with abdominal cramps
  • Nausea  and vomiting
  • The stool may contain blood and mucus

Complications of bacillary dysentery may include toxic dilation of large intestine and acute kidney disease. The best way to prevent incidences of both bacillary and amoebic dysentery is to ensure frequent hand hygiene, especially before handling food or eating and after using toilet or handling faecal matter.

Also Read: Difference Between Diarrhea And Dysentery

Difference Between Amoebic Dysentery And Bacillary Dysentery In Tabular Form

Difference In Pathology

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
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.
Margin of Ulcer Ragged and undermined. Uniform, clear-cut (sharp)

Difference In Clinical Features

Onset Slow Acute
Fever Absent Present
Abdominal Tenderness Localized Generalized
Tenesmus Absent Present

Difference In Macroscopic Features Of Stool

Number of Motions 6-8 motions in 24 hours Over 10 in 24 hours.
Amount Relatively copious Small amount
Odor Offensive (fishy odor) Odorless
Color Dark red (altered blood) Bright red (fresh blood)
Nature Blood and mucus mixed with faeces. Blood and mucus, mainly watery.
Reaction Acidic Alkaline  (for fresh blood)
Consistency Liquid or formed, mucus not adherent to the container. Viscid, mucus adherent to the container.

Difference In Microscopic Features Of Stool

RBCs In clumps Discrete, sometimes in clumps due to rouleaux formation.
Macroscopic pathology Passage of loose stool with mucus and little blood. Small, blood and mucus present but no faeces.
Pus Cells Scanty Numerous
Macrophages Few Numerous, many of them contain RBCs hence may be mistaken for E. histolytica.
Cellularity Poor High
Ghost Cell (Swollen epithelial cells) Nil Numerous
Eosinophils Present Scarce
Pyknotic Nuclear Residues  (Nuclear remains of tissue cells and leukocytes) present Absent
Charcot-Leyden (C-L) crystals Present Absent
Parasites Seen Trophozoites of E. histolytica Nil  
Bacteria Seen Numerous motile E.coli and other Enterobacteria. Scanty, non-motile shigella group or klebsiella.
Culture (Growth On MacConkey Agar) Various intestinal flora may grow. Pure growth of shigella species may be seen.

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