Amebiasis is caused by the protozoan Entamoeba histolytica. It commonly involves the intestines but can spread to other organs. Symptoms range from mild diarrhea to severe colitis or liver abscesses. Diagnosis involves identifying the trophozoites or cysts in stool or abscess samples. Treatment includes metronidazole combined with luminal amebicides like diloxanide furoate.

1. Dr.Achu Jacob Philip
Dr.Isabella

2.  Introduction
 Epidemiology
 Life cycle of Entamoeba histolytica
 Pathogenesis
 Pathology
 Clinical features
 Laboratory diagnosis
 Management

3. •Amebiasis ia an infection with the intestinal protozoan
Entamoeba histolytica.
•90% asymptomatic.
•It is the third most common cause of death from parasitic
disease.
•Asymptomatic forms are mainly caused by E.dispar.- Self
limiting (homosexual men & AIDS patients)
•Intestinal lesions mainly involve the cecum,sigmoid colon
and the rectum.
•Distant abscess occur in liver ,lung and brain.

4. Definition :
 Amoebiasis is an infection caused by Entamoeba
histolytica
with or without symptoms (WHO - 1969)
 Synonyms include entamoebiasis, amoebiosis,
amoebic
dysentery or bloody flux.

5. Global burden of the disease :
 40-50 million cases of amoebic colitis and amoebic
liver abscess
 70,000 deaths anually
 10% world population
 90% of those infected are asymptomatic, 1% may
develop invasive/extraintestinal amoebiasis.

6.  China, Central and South America, Indian
subcontinents
In India :
 Prevalence is 15% (3.6% to 47.4%)
 Maharashtra, Tamil Nadu, Chandigarh

7. Agent factors Host factors
• Virulence of organism
• Intestinal microbiota
• Sex
• Age
•Alcoholics
• Immunocompromised
(HIV) 
male homosexuals

9.  During amoebiasis there is a significant decrease in absolute
quantification of Bacteroides, Clostridium coccoides,
Clostridium leptum, Lactobacillus and an increase in
Bifdobacterium species.
 Lactobacillus species might be protective in the context of
protozoan infections (Preidis et al., 2011; Travers et al.,
2011).
 Thus a decrease in protective, commensal Lactobacillus

15. Intestinal specimen from a patient with acute
Colon (primarily
in the cecum),
sigmoid colon, and
rectum
2 types of ulcers :
nodular and irregular
Intervening
mucosal folds
may appear
normal

16. Submucosa : susceptible to the
lytic action of the parasite, and
produces
abundant microhemorrhages
Bowel
lumen
Amoebic ulcer with
neutrophilic infiltration
Mucosa
Submucos
a

19. INTESTINAL AMEBIASIS:
•Symptomatic amebic colitis develops 2-6 weeks after
ingestion of infectios cysts.
•Gradual onset of lower abdominal pain,mild
diarrhea,malaise,weight loss,back pain.
•Caecal movements may mimic acute appendicitis
•Stools will contain little fecal matter and will consist of
mainly of blood and mucus.

20. Fulminant intestinal infection
•Clinical features: Severe abdominal pain
High Fever
Profuse diarrhoea
Occurs predominantly in children
Also patients receiving glucocorticoids
Megacolon
•Patient will be having shock like features
•Severe bowel dilation with intramural air.
Syndrom of Postamebic colitis
•Persistent diarrhoea following documented cure of
amebiasis

21. AMEBIC LIVER ABSCESS:
•Febrile,Rt upper quadrent pain(dull or pleuritic) radiating to the
shoulders.
•Malaise,weight loss and hepatomegaly
•Complication
Pleuropulmonary involement (20 – 30%)
Sterile effusion
Hepatobronchial fistulae
Rupture of abscess

22. OTHER SITES
•Genitourinary Tract :
Direct extension
Genital ulcer,Profuse discharge
•Cerebral Involvement
Occurs in 0.1% patients.
Syptoms depends on size and site of lesion.

23. •Chronic granuloma arising in the large bowel.
•MC : Caecum
•Occurs in longstanding amoebic infection (with in complete treatment)
•Mistaken for carcinoma
•C/f: Pyrexia,
Mass in RIF
Blood stained mucoid diarrhoea.

24. Specimen collection :
Intestinal amoebiasis  Stool samples
Extraintestinal amoebiasis Aspirated pus

25.  Direct examination  Saline and iodine wet mounts
 Culture
 Immunodiagnosis
 Molecular methods  Polymerase chain reaction

26. Trophozoite
s
Cysts

27. Tissue amoebicides
Intestinal and Extra intestinal amoebicides
•Nitroimidazoles: Metronidazole, Tinidazole, Ornidazole,
Secnidazole, Satranidazole, Nimorazole
•Alkaloids: Emetine and Dehydroemetine
Extra intestinal amoebicides: Chloroquine
Luminal amoebicides
Amides: Diloxanide furoate, Nitazoxanide
Quinolines: Iodoquinol, Quiniodochlor
Antimicrobials: Paromomycin, Tetracyclines
To eliminate the invading trophozoites
To eradicate the intestinal cysts of Entamoeba histolytica
(source of infection)

28. Luminal amebicides
Tissue amebicides
Nitroimidazole –Metronidazole
Metronidazole 800 mg TDS x 7-10 days
(in severe cases 500 mg slow IV 6 hourly till oral therapy can be instituted)
OR
Tinidazole 2 g OD x 3 days
+
Luminal amoebicide

29. AMEBIC LIVER ABSCESS
Metronidazole 800 mg TDS x 10 days (in serious cases – IV
metronidazole x 10 days)
OR
Tinidazole 2 g oral daily x 3 - 6 days
+
Luminal amoebicide
ASPIRATION OF LIVER ABSCESS
To rule out a pyogenic abscess,mainly in multiple lesion.
No clinical response in 3 -5 days.
Threat of imminent rupture.
Left lobe abscess

30. 29yr old male came with C/o –
•Abdominal Pain
•Fever
•Vomiting
•Patient presented with dull aching pain in the right hypochondium
for 1week.
•Associated with low grade fever, with no chills or rigor
•Vomiting four episodes – mainly food particles,non bilious.
•Patient febrile not in septic shock
•Tender hepatomegaly .
TC : 16900,DC – N 86,L 10,M3,E1.
ESR : 75
LFT Normal

31. •Well defined hypoechoic
lesion 11.1 x 8.2 x 7.8
•hyperechoic septation

32. Treatment Given
•Inj Metronidazole was started .
•Pig Tail catheter inserted under local and abscess drained.
•Patient responded to treatment

33. 42 year old presented with acute abdomen
Soft ,
Hepatomegaly.

34. USG:
•Features S/o liver abscess (volume 2006cc) involving the right
lobe of liver with ? Focal subcapsular rupture.
•Moderate ascitis

35. Abscess of right lobe
of liver.

36. Sloughed out
wall of the
amebic abscess
on right lobe of
liver.

38. CT scan of the abdomen showing irregular wall thickening of the caecum.
Vinoth Boopathy et al. BMJ Case Reports 2014;2014:bcr-
2013-202616
©2014 by BMJ Publishing Group Ltd

39. Colonoscopic image showing ulcerations with yellowish white exudations in the caecum.
Vinoth Boopathy et al. BMJ Case Reports 2014;2014:bcr-
2013-202616
©2014 by BMJ Publishing Group Ltd

40. Periodic acid–Schiff stain depicting multiple trophozoites of Entamoeba histolytica (arrows).
Vinoth Boopathy et al. BMJ Case Reports 2014;2014:bcr-
2013-202616
©2014 by BMJ Publishing Group Ltd