This document provides an overview of amoebiasis (Entamoeba histolytica infection). It discusses the definition, life cycle, epidemiology, pathogenesis, clinical manifestations, diagnosis and treatment of intestinal amoebiasis as well as extra-intestinal infections such as amoebic liver abscess. Key points include that 90% of E. histolytica infections are asymptomatic but 10% can cause intestinal or extraintestinal disease ranging from dysentery to liver abscesses. Diagnosis involves microscopy of stool, biopsy or abscess aspirate samples. Treatment depends on the clinical presentation and involves metronidazole and other drugs.

1. AMOEBIASIS Dr.S.Palanivelrajan,M.D (Final Year P.G) Stanley Medical College Chennai

2. Definition Amoebiasis is an infection with intestinal protozoa Entamoeba Histolytica. 90% of infection – asymptomatic. 10% of infection – Clinical syndrome. Ranging from Dysentery to Abscess of the liver or other organs.

3. PHYLUM SARCOMASTIGOPHORA SUBPHYLUM SARCODINA SUPER CLASS RHIZOPODA CLASS LOBOSEA SUB CLASS GYMNAMOEBIA ORDER AMOEBIDA SUBORDER TUBULINA “ ENTAMOEBA HISTOLYTICA ”

4. HISTORY 1875 LOSCH – RUSSIAN. Differentiated the amoebic dysentery from bacillary dysentery by describing amoeba in the stool. 1887 KARTULIS – EGYPT. Found amoeba in the pus from a liver abscess. 1881 COUNCILMAN AND COFFLEUR. Described true bowel lesions and used the term Amoebic Dysentery. 1903 SCHAUDINN. Differentiated pathogenic and non pathogenic types of amoeba.

5. Third most common cause of death from the parasitic disease. (after schistosomiasis , Malaria) 480 Million people (world) 12% of world’s population High risk groups Travellers, immigrants, immunocompromised individual, pregnant women, sexually active male. Mental institutes, prisons, Children in day care centres. Cyst carriers Sexual transmission also occurs . EPIDEMIOLOGY

6. the intestinal lesion Gut Minute crypt lesion Extends through the muscularis mucosa and submucosa. “Flask shaped” ulcer Thrombosis of blood vessels “Toxic megacolon” Irreversible coagulation necrosis of bowel wall . PATHOLOGY

7. Tumor like lesion Several cms in length M C in caecum Multiple Histologically tissue edema patchy round cell infiltration Types intussusceptions stricture like AMOEBOMAS

8. Asymptomatic infection Mild to moderate colitis (non dysenteric colitis) Severe colitis (dysenteric colitis) Localised ulcerative lesions of the colon Localised granulomatous lesion of the colon (amoeboma) CLINICAL FINDINGS INTESTINAL AMOEBIASIS

9. DD- Amoebic Colitis Infective colitis Ulcerative colitis Colorrectal carcinoma Intestinal schistosomiasis Trichuris infection Balantidiasis Crohn’s disease Diverticulosis Ileoceacal TB

10. LABORATORY DIAGNOSIS Microscopy And Culture Wet Mount Preparation (i) mounts in saline solution (ii) mounts in saline + lodine (iii) mounts in saline + methylene blue Gomori,trichrome, Iron haematoxylin Gomori,trichrome Iron haematoxylin PAF Gomori Haematoxylin and eosin Permanently stained slide Permanently Stained slide Wet mount with enzyme digest Permanently stained slide Routine histology -PVA 10 % formalin sodium acetate acetic acid formalin -PVA, schauddins fixative None PVA, Schauddin’s Fixative Formalin 1. Stool 2. Sigmoid colon 3. Aspirate Direct Fixed 4. Biopsy Stain Examination Fixative 2. Sample

11. Enzyme Immunoassay Indirect Immunoflorescence Latex Agglutination Gel diffusion Sensitivity 60 % invasive Bowel disease 100 % with Amoeboma Immunological Test Indirect Haemagglutination

12. 500 mg t.i.d × 10 days 25 – 30 mg kg -1 day -1 in 3 doses × 7-10 days. 650 mg t.i.d × 20 days 750 – 800 mg.t.i.d × 10 days 500 mg.t.i.d × 10 days 2 g/day 2 -3 days 500 mg .t.i.d × 10 days 25 – 30 mg kg -1 day -1 in 3 doses × 7 – 10 days 1 st Choice Diloxanide Furoate 2 nd Choice Paramomycin (or) Iodoquinol 1 st Choice Metronidazole followed by diloxanide furoate ( or ) Tinidazole followed by diloxanide furoate 2 nd Choice Paramomycin Asymptomahic Intestinal carrier Intestinal infection Adult Dosage Drugs of Choice Clinical presentation

13. PREVENTION Health Education Improved water supply Chlorination – not effective Amoebic cysts Destroyed by 200 parts / 10 6 of Iodine 5 – 10 acetic acid. Heating > 68 0 C Removed by sand filtration Boling for 10 minutes kill the cysts

14. Amoebic Liver Abscess

15. This is the most common extra intestinal form of invasive amoebiasis. Adults > children ( 10 : 1 ) Male > female 20 % with past history of dysentery

16. PATHOGENESIS Journey of E. Histolytica to the Liver 1. Direct Extension from the Gut to the Liver 2. Via the Lymphatics 3. Along the portal stream Infarction – Enzymatic Dissolution

17. Clear 'halo' around an amoeba

18. Destruction of liver tissue

19. Congestion of the sinusoids

20. Pathology

21. Bulge due to superficial abscess

22. Shaggy appearance of the walls of the abscesses

23. Abscess surrounded by a distinct area of severe congestion

24. Abscess showing a thick fibrous wall

25. CLINICAL FEATURES Symptoms Pain Diarrhoea and / or Dysentery Weight Loss Cough Dyspnoea Physical findings Localized tenderness Enlarged Liver Fever Rales,rhonchi Localized intercostal tenderness Epigatric Tenderness Jaundice

26. huge abscess of the inferior surface of the left lobe.

27. Clinical enlargement of the left lobe of the liver .

28. Compression Sign

29. Point tenderness

30. Intercostal tenderness

31. Multiple large amoebic abscess seen at autopsy.

32. COMPLICATONS Right chest Peritoneum Pericardium Amoebic brain abscess - rare Hemobilia – Rupture in to major bileduct Portal hypertension

33. LABORATORY FINDINGS Normocytic Normochromic anaemia Leucocytosis -> more than 10× * 10 9 / L ESR Stool Cyst or Vegetative form of E . Histolytica LFT Bilirubin Transaminases more than 50 % Alkaline phosphatase more than 75 %

34. RADIOLOGY CXR – Elevated Right Hemi diaphragm Isotope liver scan USG Abdomen – B mode , Hypoechoic CTScan DD Subphrenic Abscess Cholecystitis Liver Hydatid cyst Primary and Secondary carcinoma of liver Lesions of the right lung and right pleura

35. Anterior view of 133/Rose Bengal dot liver scan showing a small cold area on the inferior surface of the left lobe .

36. 99m Tc sulphur colloid photo liver scan (anterior view) showing a cold area in the superior surface of the left lobe

37. X-ray chest showing obliterated costophrenic angle and an elevated right dome of the diaphragm

38. X-ray chest showing an elevated left dome of the diaphragm

39. X-ray chest showing a fluid level in a lung abscess in pulmonary amoebiasis .

40. X-ray chest showing left sided pyopneumothorax

41. X-ray chest demonstrating the more lateral and vertical spread of an empyema following a liver abscess

42. CAT SCAN

43. Peritoneoscopic view of amoebic liver abscess .

44. TREATMENT 750-800 mg.t.i.d × 10 days 500 mg t.i.d. ×10 Days 2g/day × 3-5 days 500 mg t.i.d × 10 Days 1-1.5 mg kg-1 day -1 ( max.90 mg/day ) i.v × 5 days 500 mg t.i.d × 10 days. Metronidazole followed by diloxanide furoate or tinidazole followed by diloxanide furoate dehyderoemetine followed by diloxanide furoate 1st Choice 2nd choice

45. Formal Indications To rule out a pyogenic abscess (, particularly with multiple lesions ) As adjunct to medical therapy ( No response after 72 hours ) If rupture is believed to be imminent Abscess in the left lobe where the risk of rupture is increased. Possible Indications To reduce the period of disability INDICATIONS FOR ASPIRATION OF AMOEBIC LIVER ABSCESS

46. Aspiration of flank abscess .

47. Color – Anchovy sauce, Chocolate color or pinkish brown, varying color’s Odour – Odourless Consistency – thick , Viscosity – thick lubricating Oil , Quantity – Accroding to the size of the abscess Microscopy – Dead and deformed Hepatocytes RBC’S Few Polymorphs Trphozoites of E.Histolytica present in 10 to 25 % cases Microbiology – Sterile PUS IN AMOEBIC LIVER ABSCESS Hepatoma, livercyst, Hemangimoa DD

48. A bottle of anchovy sauce and amoebic pus.

49. Bile aspirated from liver abscess

50. Different coloured pus obtained during a single session by changing the direction of the needle.

51. Chocolate coloured pus .

52. Dirty yellowish pus

53. Ivory or creamy white pus.

54. Brown coloured pus compared to anchovy sauce.

55. Pus resembling color of tea. Tea and anchovy sauce placed on either side for comparision .

56. Specks of necrotic tissue floating in the pus

57. Thin yellow pus from a 'chronic' abscess

58. ALA with Secondary infection Left lobe Abscess Bowel perforation Rupture into pericordium SURGERY

59. Haematogenous pulmonary amoebiasis without liver involvement. Haematogenous pulmonary amoebiasis with independent liver abscess. Pulmonary amoebiasis extending from a liver abscess. Broncho hepatie fistula with pulmonary involvement. Empyema entering from a liver abscess PULMONARY AMOEBIASIS

60. PERITONEAL AMOEBIASIS PERICARDIAL AMOEBIASIS CEREBRAL AMOEBIASIS GENITO URINARY AMOEBIASIS CUTANEOUS AMOEBIASIS

61. FREE LIVING AMOEBAE

62. PRIMARY AMOEBIC MENINGO ENCEPHALITIS Negleria fowleri Swimming -> 2 – 14 days Cribriform plate -> olfactory -> sub arachnoid space Like meningitis picture 200 cases since 1965 , young adults and children Amphotericin B 1 mg / kg per day

63. Acanthamoeba – 5 species MC by A.Castellani, A.Polyphaga Local propamide and neomycin Corneal grafting Contact lense users – Avoid raw tap water Most appropriate – Chlorhexidine and hydrogen peroxide AMOEBIC KERATITIS Balamuthia mandriallaris 60 cases since 1990 Albendazole and itraconazole AMOEBIC MENINGO ENCEPHALITIS

64. Thank You