Amebiasis: Difference between revisions
(Marked this version for translation)
 
(23 intermediate revisions by 8 users not shown)
Line 1: Line 1:
==Background==
<languages/>
* Fecal oral transmission of Entamoeba histolytica cyst
<translate>
* Excystation in intestinal lumen
 
* Trophozoites adhere and colonizes large intestine forming new cysts or invade the intestinal mucosa to cause colitis or abscesses
 
* Liver abscess-10x more common in men
==Background== <!--T:1-->
==Clinical Features==
 
* Asymptomatic vs. dysentery vs. extraintestinal abscesses
<!--T:2-->
* Intestinal- several weeks of crampy abdominal pain, weight loss, watery or bloody diarrhea
[[File:Amebiasis LifeCycle.gif|thumb|The life-cycle of various intestinal Entamoeba species.]]
* Liver abscess-fever, cough, RUQ or epigastric pain, right-sided pleural pain or referred shoulder pain +/- GI upset
*Fecal oral transmission of Entamoeba histolytica cyst
** Hepatomegaly with tenderness over the liver a typical finding
*Most infection asymptomatic
*Excystation in intestinal lumen
*Trophozoites adhere and colonizes large intestine forming new cysts or invade the intestinal mucosa to cause colitis or abscesses
*[[Special:MyLanguage/Liver abscess|Liver abscess]] - 10x more common in men
*Incubation period usually 2-4 weeks, but may range from a few days to years
 
 
 
==Clinical Features== <!--T:3-->
 
<!--T:4-->
*Asymptomatic vs. dysentery vs. extraintestinal abscesses
*Intestinal- several weeks of crampy [[Special:MyLanguage/abdominal pain|abdominal pain]], weight loss, watery or bloody [[Special:MyLanguage/diarrhea|diarrhea]]
*[[Special:MyLanguage/Liver abscess|Liver abscess]]-[[Special:MyLanguage/fever|fever]], [[Special:MyLanguage/cough|cough]], [[Special:MyLanguage/RUQ pain|RUQ]] or [[Special:MyLanguage/epigastric pain|epigastric pain]], right-sided [[Special:MyLanguage/chest pain|pleural pain]] or referred shoulder pain +/- GI upset
**[[Special:MyLanguage/Hepatomegaly|Hepatomegaly]] with tenderness over the liver a typical finding
**Abscess rupture can involve associated peritoneum, pericardium, or pleural cavity
**Abscess rupture can involve associated peritoneum, pericardium, or pleural cavity
* Extrahepatic amebic abscesses in the lung, brain, and skin are rare
*Extrahepatic amebic abscesses in the lung, brain, and skin are rare
 
 
 
==Differential Diagnosis== <!--T:5-->
 
 
===Dysentery=== <!--T:6-->
 
<!--T:7-->
*Infectious- [[Special:MyLanguage/shigella|shigella]], [[Special:MyLanguage/salmonella|salmonella]], [[Special:MyLanguage/campylobacter|campylobacter]], [[Special:MyLanguage/E. Coli|E. Coli]].
*Noninfectious- [[Special:MyLanguage/Inflammatory bowel disease|Inflammatory bowel disease]], [[Special:MyLanguage/ischemic colitis|ischemic colitis]], [[Special:MyLanguage/diverticulitis|diverticulitis]], AV malformation.


==Differential Diagnosis==
</translate>
===Dysentery===
{{Liver abscess DDX}}
*Infectious- Shigella, Salmonella, Campylobacter, E.Coli.
<translate>
*Noninfectious- Inflammatory bowel disease, ischemic colitis, diverticulitis, AV malformation.
===Liver abscess===
*Pyogenic liver abscess, necrotic hepatoma, Echinococcal cyst


</translate>
{{Fever in Traveler DDX}}
{{Fever in Traveler DDX}}
<translate>


</translate>
{{Diarrhea DDX}}
{{Diarrhea DDX}}
<translate>
==Evaluation== <!--T:8-->
===Labs=== <!--T:9-->


==Diagnosis==
<!--T:10-->
*CBC
*CBC
*Chem
*Chem
*LFT
*[[Special:MyLanguage/LFTs|LFTs]]
*Stool or abscess microscopy
*Stool PCR
**Diagnostic gold standard
**100% sensitive and specific
*Stool or abscess microscopy  
**<60% SN; unreliable diagnostic test<ref>Rayan HZ. Microscopic overdiagnosis of intestinal amoebiasis. J Egypt Soc Parasitol. 2005;35(3):941–951</ref>
*Stool, serum, or abscess fluid antigen
*Stool, serum, or abscess fluid antigen
*Indirect hemagluttination (antibody)
*Indirect hemagglutination (antibody)
 
 
 
===Imaging=== <!--T:11-->
 
<!--T:12-->
*Abdominal Ultrasound
**58-98% SN for liver abscess (depending on size/location)
*Abdominal CT
**Alternative to ultrasound; equally effective in identifying abscess
 
 
 
==Management== <!--T:13-->
 
 
===Asymptomatic colonization=== <!--T:14-->
 
<!--T:15-->
*[[Special:MyLanguage/Paromomycin|Paromomycin]] or diloxanide
 
 
 
===Colitis=== <!--T:16-->
 
<!--T:17-->
*[[Special:MyLanguage/Metronidazole|Metronidazole]]
 
 
 
===Liver abscess=== <!--T:18-->
 
<!--T:19-->
*[[Special:MyLanguage/Flagyl|Flagyl]], [[Special:MyLanguage/tinidazole|tinidazole]], [[Special:MyLanguage/paromomycin|paromomycin]], or diloxanide
*Consider drainage of abscess by IR if no response to antibiotics in 5 days, abscess > 5cm, or left lobe involvement
 
 
 
==Disposition== <!--T:20-->
 
<!--T:21-->
*'''Admission'''
**Admit if signs of shock, sepsis, or peritonitis
**Patients with toxic megacolon should be admitted for surgical intervention.
*'''Discharge'''
**Patients who are non-toxic and able to tolerate oral hydration/PO meds can be discharged with outpatient follow-up
 
 
 
==External Links== <!--T:22-->
 
<!--T:23-->
*[https://www.merckmanuals.com/professional/infectious-diseases/intestinal-protozoa-and-microsporidia/amebiasis?query=amebiasis Merk Manual - Amebiasis]
 
 


==Management==
==References== <!--T:24-->
===Asymptomatic colonization===
 
*Paromomycin or Diloxanide
<!--T:25-->
===Colitis===
*Flagyl
===Liver abscess===
*Flagyl, Tinidazole, Paromomycin, or Diloxanide
*Consider drainage of abscess if no response to abx in 5 days, abscess >5cm or left lobe involvement
==Disposition==
*Home if no complications
==References==
<references/>
<references/>


<!--T:26-->
[[Category:ID]]
[[Category:ID]]
[[Category:TropMed]]
[[Category:Tropical Medicine]]
[[Category:GI]]
[[Category:GI]]
</translate>

Latest revision as of 20:29, 6 January 2026

Other languages:


Background

The life-cycle of various intestinal Entamoeba species.
  • Fecal oral transmission of Entamoeba histolytica cyst
  • Most infection asymptomatic
  • Excystation in intestinal lumen
  • Trophozoites adhere and colonizes large intestine forming new cysts or invade the intestinal mucosa to cause colitis or abscesses
  • Liver abscess - 10x more common in men
  • Incubation period usually 2-4 weeks, but may range from a few days to years


Clinical Features

  • Asymptomatic vs. dysentery vs. extraintestinal abscesses
  • Intestinal- several weeks of crampy abdominal pain, weight loss, watery or bloody diarrhea
  • Liver abscess-fever, cough, RUQ or epigastric pain, right-sided pleural pain or referred shoulder pain +/- GI upset
    • Hepatomegaly with tenderness over the liver a typical finding
    • Abscess rupture can involve associated peritoneum, pericardium, or pleural cavity
  • Extrahepatic amebic abscesses in the lung, brain, and skin are rare


Differential Diagnosis

Dysentery

Hepatic abscess

Fever in traveler

Acute diarrhea

Infectious

Noninfectious

Watery Diarrhea

Traveler's Diarrhea


Evaluation

Labs

  • CBC
  • Chem
  • LFTs
  • Stool PCR
    • Diagnostic gold standard
    • 100% sensitive and specific
  • Stool or abscess microscopy
    • <60% SN; unreliable diagnostic test[2]
  • Stool, serum, or abscess fluid antigen
  • Indirect hemagglutination (antibody)


Imaging

  • Abdominal Ultrasound
    • 58-98% SN for liver abscess (depending on size/location)
  • Abdominal CT
    • Alternative to ultrasound; equally effective in identifying abscess


Management

Asymptomatic colonization


Colitis


Liver abscess

  • Flagyl, tinidazole, paromomycin, or diloxanide
  • Consider drainage of abscess by IR if no response to antibiotics in 5 days, abscess > 5cm, or left lobe involvement


Disposition

  • Admission
    • Admit if signs of shock, sepsis, or peritonitis
    • Patients with toxic megacolon should be admitted for surgical intervention.
  • Discharge
    • Patients who are non-toxic and able to tolerate oral hydration/PO meds can be discharged with outpatient follow-up


External Links


References

  1. ↑ Marx et al. “Cholera and Gastroenteritis caused by Noncholera Vibrio Species”. Rosen’s Emergency Medicine 8th edition vol 1 pg 1245-1246.
  2. ↑ Rayan HZ. Microscopic overdiagnosis of intestinal amoebiasis. J Egypt Soc Parasitol. 2005;35(3):941–951
Retrieved from "https://www.wikem.org/w/index.php?title=Amebiasis&oldid=379779"