Amebic dysentery vs Bacillary dysentery
How to tell Amebic dysentery and Bacillary dysentery apart when a board question makes them look alike.
Amebic = E. histolytica trophozoites with ingested RBCs and liver abscess risk; bacillary = acute bacterial inflammatory diarrhea with fecal neutrophils.
Side by side
Amebic dysentery from Entamoeba histolytica causes gradual bloody diarrhea, flask-shaped ulcers, trophozoites with ingested RBCs, and risk of liver abscess with anchovy-paste material.
Bacillary dysentery from invasive bacteria such as Shigella, Campylobacter, Salmonella, or EIEC causes acute fever, cramps, tenesmus, and bloody/purulent diarrhea with many fecal leukocytes.
E. histolytica cysts are ingested, trophozoites invade colonic mucosa, and portal spread can seed the liver.
Invasive or toxin-producing bacteria damage intestinal mucosa, causing inflammatory diarrhea with neutrophils and blood.
Travel, cyst ingestion, trophozoites with RBCs, serology/antigen/PCR, flask-shaped ulcers, and liver abscess support amebiasis.
Stool culture/PCR with invasive bacteria, high fever, fecal leukocytes/lactoferrin, tenesmus, and outbreak exposure support bacillary dysentery.
The trap
Both cause bloody diarrhea, so parasite microscopy/liver abscess clues versus acute bacterial fever/neutrophils decide.
The repair move
For dysentery, separate protozoal invasion and liver abscess from acute bacterial inflammatory diarrhea.
Try a free question
CoreA traveler has subacute bloody diarrhea and right upper quadrant pain; stool shows trophozoites containing ingested red blood cells and imaging shows a liver abscess. Which diagnosis is most likely?
Show answer and explanation
Answer: A. Amebic dysentery. Trophozoites with ingested RBCs plus liver abscess support Entamoeba histolytica amebic dysentery.
Why the other choices are tempting
- B. Bacillary dysentery is acute bacterial inflammatory diarrhea with fecal leukocytes.
- C. Giardiasis causes foul greasy diarrhea and malabsorption.
- D. Cryptosporidiosis causes watery diarrhea, severe in AIDS.
- E. Cholera causes profuse watery rice-water diarrhea.
Flashcards
Tap a card to flip it.
What stool microscopy clue supports Entamoeba histolytica?
Trophozoites containing ingested red blood cells support Entamoeba histolytica.
What ulcer shape is classic for amebic dysentery?
Flask-shaped ulcers are classic for amebic dysentery.
Quick answers
What is the fastest way to tell Amebic dysentery from Bacillary dysentery?
Amebic = E. histolytica trophozoites with ingested RBCs and liver abscess risk; bacillary = acute bacterial inflammatory diarrhea with fecal neutrophils.
What is the key clue for Amebic dysentery?
Amebic dysentery from Entamoeba histolytica causes gradual bloody diarrhea, flask-shaped ulcers, trophozoites with ingested RBCs, and risk of liver abscess with anchovy-paste material.
What is the key clue for Bacillary dysentery?
Bacillary dysentery from invasive bacteria such as Shigella, Campylobacter, Salmonella, or EIEC causes acute fever, cramps, tenesmus, and bloody/purulent diarrhea with many fecal leukocytes.
What is the common trap with Amebic dysentery vs Bacillary dysentery?
Both cause bloody diarrhea, so parasite microscopy/liver abscess clues versus acute bacterial fever/neutrophils decide.