Entamoeba histolytica: Difference between revisions

Revision as of 13:01, 24 August 2020

Background

Microbiology

Intestinal protozoan parasite within the genus Entamoeba
Microscopically distinguishable from the non-pathogenic E. dispar, E. moshkovskii, and E. bangladeshii

Epidemiology

Present worldwide, but most disease occurs in the developing world
Causes 34 to 50 million cases annually and up to 100,000 deaths

Clinical Manifestations

Amoebic Diarrhea and Dysentery

Amoebic diarrhea, with or without dysentery, is common
- About 15 to 30% of cases involve amoebic dysentery (with macroscopic or microscopic blood)
Typically a subacute onset over 3 to 4 weeks and abdominal pain
- However, can be up to months
Fever is rare, even in dysentery
In children, can lead to intussusception, perforation, and necrotizing colitis

Amoebic Liver Abscess

Amoebic liver abscess is far more common in men than women, and rare in children
Symptoms progress over 2 to 4 weeks, with fever, cough, and abdominal pain
- The pain is typically a dull ache in the right upper quadrant or epigastrium

Disseminated Amoebiasis

Metastatic infections are possible, most often from direct extension of a liver abscess
Most commonly spreads to chest, with empyema, bronchohepatic fistula, pericarditis
Cerebral disease is rare but can happen

Diagnosis

Microscopically indistinguishable from the non-pathogenic E. dispar, so needs molecular tests to confirm diagnosis

Management

Liver Abscess

Either
- Metronidazole 750 mg PO tid for 10 days, or
- Tinidazole 2 g PO daily for 5 days
Followed by a luminal agent, either
- Paramomycin 10 mg/kg PO tid for 5 to 10 days, or
- Diloxanide furoate 500 mg PO tid for 10 days
May need surgery or aspiration if the lesion is large or medication has failed

Diarrhea

Tinidazole 2 g PO daily for 5 days
Followed by a luminal agent, as above

Asymptomatic carriage

Treat with a luminal agent, as above

@@ Line 1: / Line 1: @@
-== Background ==
+==Background==
-=== Microbiology ===
+===Microbiology===
-* Intestinal protozoan parasite within the genus ''[[Entamoeba species|Entamoeba]]''
-* Microscopically distinguishable from the non-pathogenic ''E. dispar'', ''E. moshkovskii'', and ''E. bangladeshii''
+*Intestinal protozoan parasite within the genus ''[[Entamoeba species|Entamoeba]]''
-=== Epidemiology ===
+*Microscopically distinguishable from the non-pathogenic ''E. dispar'', ''E. moshkovskii'', and ''E. bangladeshii''
-* Present worldwide, but most disease occurs in the developing world
-* Causes 34 to 50 million cases annually and up to 100,000 deaths
+===Epidemiology===
-== Clinical Manifestations ==
-=== Amoebic diarrhea and dysentery ===
-* [[Causes::Amoebic diarrhea]], with or without dysentery, is common
-** About 15 to 30% of cases involve [[Causes::amoebic dysentery]] (with macroscopic or microscopic blood)
-* Typically a subacute onset over 3 to 4 weeks and abdominal pain
-** However, can be up to months
-* Fever is rare, even in dysentery
-* In children, can lead to intussusception, perforation, and necrotizing colitis
+*Present worldwide, but most disease occurs in the developing world
-=== Amoebic liver abscess ===
+*Causes 34 to 50 million cases annually and up to 100,000 deaths
-* [[Causes::Amoebic liver abscess]] is far more common in men than women, and rare in children
-* Symptoms progress over 2 to 4 weeks, with fever, cough, and abdominal pain
-** The pain is typically a dull ache in the right upper quadrant or epigastrium
+==Clinical Manifestations==
-=== Disseminated amoebiasis ===
+===Amoebic Diarrhea and Dysentery===
-* Metastatic infections are possible, most often from direct extension of a liver abscess
-* Most commonly spreads to chest, with empyema, bronchohepatic fistula, pericarditis
-* Cerebral disease is rare but can happen
+*[[Causes::Amoebic diarrhea]], with or without dysentery, is common
-== Diagnosis ==
+**About 15 to 30% of cases involve [[Causes::amoebic dysentery]] (with macroscopic or microscopic blood)
-* Microscopically distinguishable from the non-pathogenic ''E. dispar'', so needs molecular tests to confirm diagnosis
+*Typically a subacute onset over 3 to 4 weeks and abdominal pain
+**However, can be up to months
+*Fever is rare, even in dysentery
+*In children, can lead to intussusception, perforation, and necrotizing colitis
+===Amoebic Liver Abscess===
-== Management ==
-=== Liver abscess ===
-* Either
-** [[Is treated with::Metronidazole]] 750 mg PO tid for 10 days
-** [[Is treated with::Tinidazole]] 2 g PO daily for 5 days
-* Followed by a luminal agent, either
-** [[Is treated by::Paramomycin]] 10 mg/kg PO tid for 5 to 10 days
-** [[Is treated by::Diloxanide furoate]] 500 mg PO tid for 10 days
+*[[Causes::Amoebic liver abscess]] is far more common in men than women, and rare in children
-=== Diarrhea ===
+*Symptoms progress over 2 to 4 weeks, with fever, cough, and abdominal pain
-* [[Is treated by::Tinidazole]] 2 g PO daily for 5 days
+**The pain is typically a dull ache in the right upper quadrant or epigastrium
-* Followed by a luminal agent, as above
+===Disseminated Amoebiasis===
-=== Asymptomatic carriage ===
-* Treat with a luminal agent, as above
+*Metastatic infections are possible, most often from direct extension of a liver abscess
+*Most commonly spreads to chest, with empyema, bronchohepatic fistula, pericarditis
+*Cerebral disease is rare but can happen
+==Diagnosis==
+*Microscopically indistinguishable from the non-pathogenic ''E. dispar'', so needs molecular tests to confirm diagnosis
+==Management==
+===Liver Abscess===
+*Either
+**[[Is treated with::Metronidazole]] 750 mg PO tid for 10 days, or
+**[[Is treated with::Tinidazole]] 2 g PO daily for 5 days
+*Followed by a luminal agent, either
+**[[Is treated by::Paramomycin]] 10 mg/kg PO tid for 5 to 10 days, or
+**[[Is treated by::Diloxanide furoate]] 500 mg PO tid for 10 days
+*May need surgery or aspiration if the lesion is large or medication has failed
+===Diarrhea===
+*[[Is treated by::Tinidazole]] 2 g PO daily for 5 days
+*Followed by a luminal agent, as above
+===Asymptomatic carriage===
+*Treat with a luminal agent, as above
 {{DISPLAYTITLE:''Entamoeba histolytica''}}
 [[Category:Protozoa]]