This document discusses amoebic liver abscesses caused by the parasite Entamoeba histolytica. It begins by explaining that E. histolytica can infect the gastrointestinal tract and spread to other organs like the liver, potentially causing liver abscesses. It then provides more details on the clinical presentation of amoebic liver abscesses, noting that they most commonly occur in people aged 20-45 and present with symptoms like abdominal pain, fever, and anorexia. The document also discusses diagnosis of liver abscesses via ultrasound and treatment options for E. histolytica infection like metronidazole.
2. Amoebiasis is the infection of the human gastrointestinal
tract by Entamoeba histolytica, a parasite that is capable of
invading the intestinal mucosa and may spread to other
organs, mainly the liver. Entamoeba dispar, an amoeba
morphologically similar to E. histolytica also colonises the
human gut and has been recognised recently as a
separate species with no disease potential1-4. The
acceptance of E. dispar as a distinct but closely related
protozoan species has had a major implication in the
epidemiology of amoebiasis, since most asymptomatic
infections are now attributed to this non-invasive amoeba.
E. histolytica infection may have intestinal as well as extra-
intestinal manifestations
Introducton:
4. AMOEBIC LIVER ABSCESSES
It is an inflammatory space- occupying lesion of the liver caused
by Entamoeba histolytica. The incidence of ALA has been
reported to vary between 3% and 9% of all cases of amoebiasis5
. In India ALA is endemic. The diagnosis of this condition has
undergone major changes after the advent of advances in
imaging and molecular biology techniques. This has also enabled
a reappraisal of the disease with recognition of the wide variety
of clinical presentations and multitude of complications.
5. CLINICALPRESENTATION -
Amoebic liver abscess occurs most commonly in the age group of 20 to 45 years. It
has been noted infrequently at 108 Journal, Indian Academy of Clinical Medicine Vol.
4, No. 2 April-June 2003 the extremes of age and is seven to nine times more
common in males. ALA may present as an acute process or as a chronic indolent
disease. It has been classified by the duration of illness and severity into :
i. Acute
-- Acute benign
– Acute aggressive
ii. Chronic
– Chronic benign
– Chronic accelerated
Most patients present with an acute illness and duration of symptoms less than 2
weeks. The main presenting features are abdominal pain, fever, and anorexia.
Abdominal pain is usually moderate and localised to the right upper quadrant or to
the epigastrium. Diffuse abdominal pain, pleuritic chest pain, and radiation of right
upper quadrant pain to the right shoulder are not uncommon.
6. Multiple liver abscesses :
Fifteen per cent of patients may have multiple abscesses. They
present with fever, toxaemia, deep jaundice, and encephalopathy. Toxaemia is
suggestive of an added bacterial infection leading to a more severe disease.
E.coli and Klebseilla are the commonly cultured organisms. These patients
present with a clinical picture indistinguishable from hepatic encephalopathy
due to acute hepatocellular failure. Hepatic encephalopathy in ALA patients
possibly results from combination of right hepatic vein occlusion, pylophlebitis,
and occlusion of several portal vein radicles
7. DIAGNOSIS
Ultrasound is very useful for diagnosis of amoebic liver abscess. The
classic appearance is a non-homogeneous, hypoechoic, round or oval
mass with well defined borders. Complete resolution of an amoebic
liver abscess may take upto two years. Occasionally, percutaneous
diagnostic needle aspiration may be needed to differentiate between
amoebic and pyogenic liver abscess.
8. PHARMACOTHERAPY FOR E. HISTOLYTICA INFECTION IN
ADULTS
Intraluminal Infection
Diloxanide furoate 500 mg tid X 20 days
Paromomycin 30 mg/kg/day X 10 days (in 3 divided doses) Iodoquinol 650 mg tid X 20 days
Invasive colitis
Metronidazole 800 mg tid X 5 days
Tinidazole 1 gm bd X 3 days
Amoebic liver abscess
Metrinidazole 800 mg tid PO X 10 days (500 mg qid IV)
