Amoebiasis Amoebiasis

Dr. Ashok Jaisingani Dr. Ashok Jaisingani

Introduction Introduction

► Amoebiasis is caused by Entamoeba histolytica Amoebiasis is caused by Entamoeba histolytica ► The majority of infected individuals are remain The majority of infected individuals are remain

asymptomatic carriers. asymptomatic carriers. ► The mode is via faeco – oral route. The mode is via faeco – oral route. ► Disease occurs as a result of substandard hygiene Disease occurs as a result of substandard hygiene

and sanitation.and sanitation.► Amoebic liver abscess is the commonest Amoebic liver abscess is the commonest

extraintestinal manifestation, occurs in less than extraintestinal manifestation, occurs in less than 10%. In endemic areas it is much more common 10%. In endemic areas it is much more common than pyogenic abscess. than pyogenic abscess.

► Pts who are immunocompromised or alcoholic are Pts who are immunocompromised or alcoholic are more susceptible to infection. more susceptible to infection.

Pathogenesis Pathogenesis

► The organisms enter the gut through food and The organisms enter the gut through food and water contaminated with cyst. water contaminated with cyst.

► In small bowl hatching of cyst result into large In small bowl hatching of cyst result into large number of trophozytes which reached to colon number of trophozytes which reached to colon where “Flask Shaped Ulcer” form in the submucosa. where “Flask Shaped Ulcer” form in the submucosa.

► The trophozytes multiply, ultimately forming cyst The trophozytes multiply, ultimately forming cyst which enter the portal circulation reach to liver, which enter the portal circulation reach to liver, where they multiply in portal triad causing focal where they multiply in portal triad causing focal infarction of hepatocytes and liquificative necrosis infarction of hepatocytes and liquificative necrosis (liver abscess), and also passed in the faces as an (liver abscess), and also passed in the faces as an infective form that infect other humane being as infective form that infect other humane being as result of unsanitary conditions. result of unsanitary conditions.

Amoebic Liver Abscess Amoebic Liver Abscess

► The right lobe is involved in 80% of the cases, The right lobe is involved in 80% of the cases, the left in 10% and rest are multiple. the left in 10% and rest are multiple.

► The abscess are most common high in The abscess are most common high in diaphragmatic surface of right lobe, this may diaphragmatic surface of right lobe, this may cause pulmonary symptoms and chest cause pulmonary symptoms and chest complication. complication.

► The abscess cavity contain chocolate colored, The abscess cavity contain chocolate colored, odorless, anchovy sauce – like fluid that is odorless, anchovy sauce – like fluid that is mixture of the necrotic liver tissue and blood.mixture of the necrotic liver tissue and blood.

► Untreated abscess are likely to be rupture. Untreated abscess are likely to be rupture. While pus in abscess is sterile unless While pus in abscess is sterile unless secondarily infected secondarily infected

Chronic Amoebic Infection Of Chronic Amoebic Infection Of Large BowlLarge Bowl

►Chronic Infection of large bowl may Chronic Infection of large bowl may result into granulomatous lesion along result into granulomatous lesion along the large bowl, most commonly seen the large bowl, most commonly seen in caecum called as “Amoeboma” in caecum called as “Amoeboma”

Clinical Features Clinical Features

► Typical pts with amoebic liver disease is young Typical pts with amoebic liver disease is young adult male with history of “Pain and fever” with adult male with history of “Pain and fever” with insidious onset of non – specific symptoms insidious onset of non – specific symptoms - Anorexia - Anorexia - Night Sweats - Night Sweats - Malaise - Malaise - Cough - Cough

► Then gradually more specific symptoms such as Then gradually more specific symptoms such as 1- Pain in right upper abdomen, shoulder tip pain 1- Pain in right upper abdomen, shoulder tip pain 2- Hicoughs2- Hicoughs3- Non – productive cough 3- Non – productive cough

► There may also be past history of bloody diarrhea There may also be past history of bloody diarrhea or travel to endemic areas raise the suspicious or travel to endemic areas raise the suspicious index. index.

Clinical Examination Clinical Examination

► Examination reveals pt who is toxic and anemic Examination reveals pt who is toxic and anemic ► Pt will have upper abdominal rigidity Pt will have upper abdominal rigidity ► Hepatomegaly Hepatomegaly ► Tender & bulging intercostal space Tender & bulging intercostal space ► Overlying skin edema Overlying skin edema ► Pleural Effusion Pleural Effusion ► Basal pneumonitis (usually late manifestation) Basal pneumonitis (usually late manifestation) ► There may be jaundice or ascites also presentThere may be jaundice or ascites also present► Rarely there may be rupture of abscess cavity into Rarely there may be rupture of abscess cavity into

peritoneum, pleural space or pericardial cavity and peritoneum, pleural space or pericardial cavity and pts present as an emergency. pts present as an emergency.

How To Differentiate Amoeboma How To Differentiate Amoeboma From Right Sided Colon Cancer?From Right Sided Colon Cancer?►An amoeboma should be suspected when An amoeboma should be suspected when

a patient from endemic area with a patient from endemic area with generalized ill health and pyrexia have a generalized ill health and pyrexia have a mass in right iliac fossae, with history of mass in right iliac fossae, with history of blood stained mucoid diarrhea. blood stained mucoid diarrhea.

►Such type of pts is highly unlikely to have Such type of pts is highly unlikely to have carcinoma as “altered bowl habit” is not carcinoma as “altered bowl habit” is not feature of right sided colon cancer. feature of right sided colon cancer.

Investigation Investigation

► Haematological Tests Haematological Tests ► Biochemical Tests Biochemical Tests ► Serological Tests (more specific to detect Serological Tests (more specific to detect

antibodies) are antibodies) are 1- Test for compliment fixation1- Test for compliment fixation2- Indirect haemagglutination assay (IHA) 2- Indirect haemagglutination assay (IHA) 3- Indirect Immunoflourescence3- Indirect Immunoflourescence4- Enzyme – like Immunosorbent assay (ELISA) 4- Enzyme – like Immunosorbent assay (ELISA)

► IHA has very high sensitivity rate in acute amoebic IHA has very high sensitivity rate in acute amoebic liver abscess in non – endemic region and remain liver abscess in non – endemic region and remain elevated for some time. elevated for some time.

► An outpatient rigid sigmoidoscopy using disposable An outpatient rigid sigmoidoscopy using disposable instrument is very useful particularly if pts complain instrument is very useful particularly if pts complain bloody mucoid diarrhea. bloody mucoid diarrhea.

Haemetological & Biochemical Haemetological & Biochemical Tests Tests

►These investigation reflects the presence These investigation reflects the presence of chronic infective process with of chronic infective process with 1- Anemia 1- Anemia 2- Leucocytosis 2- Leucocytosis 3- Elevated ESR 3- Elevated ESR 4- Elevated C – reactive protein 4- Elevated C – reactive protein 5- Hypoalbunaemia 5- Hypoalbunaemia 6- Deranged Liver Function Test 6- Deranged Liver Function Test 7- Elevated alkaline phosphate 7- Elevated alkaline phosphate

Sigmoidoscopy Sigmoidoscopy

►Sigmoidoscopy show shallow skip Sigmoidoscopy show shallow skip lesion and flask shaped or “collar – lesion and flask shaped or “collar – stud” undermine ulcer may be seen stud” undermine ulcer may be seen and can be biopsied or scraping can be and can be biopsied or scraping can be taken along with mucus for taken along with mucus for microscopic examination. microscopic examination.

►Presence of trophozoites distinguish Presence of trophozoites distinguish the condition from ulcerative collitis. the condition from ulcerative collitis.

Imaging TechniqueImaging Technique

►Ultrasound and CT – scan are the Ultrasound and CT – scan are the imaging method of the choice.imaging method of the choice.

►Ultrasound investigation is very Ultrasound investigation is very accurate and is used for aspiration, accurate and is used for aspiration, both diagnostic and therapeutic both diagnostic and therapeutic purpose. purpose.

►Doubtful cases CT – scan confirm the Doubtful cases CT – scan confirm the diagnosis. diagnosis.

Amoebic TreatmentAmoebic Treatment► Medical treatment is very effective should be first choice.Medical treatment is very effective should be first choice.► Metronidazole and tinidazole are effective drugsMetronidazole and tinidazole are effective drugs► Diloxanide furoate, not effective against hepatic infestation is Diloxanide furoate, not effective against hepatic infestation is

used for 10 days to destroy intestinal amoeba used for 10 days to destroy intestinal amoeba ► In large abscess repeated aspiration is combined with drug In large abscess repeated aspiration is combined with drug

treatment, threshold for aspiring abscess in left lobe is lower treatment, threshold for aspiring abscess in left lobe is lower because its predilection for rupturing into pericardium. because its predilection for rupturing into pericardium.

► Surgical treatment reserve for the complication such as Surgical treatment reserve for the complication such as rupture into pleural, peritoneal or pericardial cavity. rupture into pleural, peritoneal or pericardial cavity.

► Resuscitation, Drainage and appropriate lavage with vigorous Resuscitation, Drainage and appropriate lavage with vigorous medical treatment are key principles. medical treatment are key principles.

► Acute toxic megacolon and hemorrhage are intestinal Acute toxic megacolon and hemorrhage are intestinal complication that are treated with intensive supportive complication that are treated with intensive supportive therapy followed by resection and exteriorisation. therapy followed by resection and exteriorisation.

► When an amoeboma is suspected in a colonic mass cancer When an amoeboma is suspected in a colonic mass cancer should be excluded by appropriate imaging. should be excluded by appropriate imaging.