Podcast
Questions and Answers
What is the initial treatment for amoebiasis involving abscess aspiration?
What is the initial treatment for amoebiasis involving abscess aspiration?
Which of the following conditions is not effectively treated with Metronidazole?
Which of the following conditions is not effectively treated with Metronidazole?
What percentage of the drug is excreted unchanged in the urine?
What percentage of the drug is excreted unchanged in the urine?
Which side effect is commonly associated with Metronidazole treatment?
Which side effect is commonly associated with Metronidazole treatment?
Signup and view all the answers
What is the recommended dosage of Tinidazole for treating giardiasis?
What is the recommended dosage of Tinidazole for treating giardiasis?
Signup and view all the answers
What is the primary method through which Giardia infections are acquired?
What is the primary method through which Giardia infections are acquired?
Signup and view all the answers
Which stage of Giardia lamblia is responsible for disrupting the intestinal border?
Which stage of Giardia lamblia is responsible for disrupting the intestinal border?
Signup and view all the answers
What is a common symptom associated with Giardia lamblia infection?
What is a common symptom associated with Giardia lamblia infection?
Signup and view all the answers
What is the duration of the incubation period for Giardia lamblia infection?
What is the duration of the incubation period for Giardia lamblia infection?
Signup and view all the answers
Which management option is commonly prescribed for treating Giardia lamblia infection?
Which management option is commonly prescribed for treating Giardia lamblia infection?
Signup and view all the answers
What characterizes chronic amoebic dysentery?
What characterizes chronic amoebic dysentery?
Signup and view all the answers
Which condition can be confused with an amoeboma?
Which condition can be confused with an amoeboma?
Signup and view all the answers
What is the major indication of acute liver abscess due to E. histolytica infection?
What is the major indication of acute liver abscess due to E. histolytica infection?
Signup and view all the answers
Which of the following antibiotics is primarily tissue amebicidal?
Which of the following antibiotics is primarily tissue amebicidal?
Signup and view all the answers
Which symptom is NOT characteristic of right lobe liver abscess?
Which symptom is NOT characteristic of right lobe liver abscess?
Signup and view all the answers
What is a common complication associated with chronic amoebic dysentery?
What is a common complication associated with chronic amoebic dysentery?
Signup and view all the answers
Which of the following is a common laboratory finding in patients with liver abscess?
Which of the following is a common laboratory finding in patients with liver abscess?
Signup and view all the answers
What is the role of diloxanide furoate in amoebic dysentery treatment?
What is the role of diloxanide furoate in amoebic dysentery treatment?
Signup and view all the answers
Which type of amoeba is considered invasive and associated with tissue damage?
Which type of amoeba is considered invasive and associated with tissue damage?
Signup and view all the answers
What is the primary route of transmission for Entamoeba histolytica?
What is the primary route of transmission for Entamoeba histolytica?
Signup and view all the answers
Which of the following describes the lesions caused by E.histolytica infection?
Which of the following describes the lesions caused by E.histolytica infection?
Signup and view all the answers
What is the typical incubation period for amoebic colitis caused by E.histolytica?
What is the typical incubation period for amoebic colitis caused by E.histolytica?
Signup and view all the answers
Which symptom is commonly associated with severe dysentery caused by E.histolytica?
Which symptom is commonly associated with severe dysentery caused by E.histolytica?
Signup and view all the answers
What is the fate of cysts of E.histolytica in infected individuals?
What is the fate of cysts of E.histolytica in infected individuals?
Signup and view all the answers
What distinguishes the comorbidity of mild amoebic colitis?
What distinguishes the comorbidity of mild amoebic colitis?
Signup and view all the answers
Which area of the gastrointestinal tract is most frequently affected by E.histolytica?
Which area of the gastrointestinal tract is most frequently affected by E.histolytica?
Signup and view all the answers
Study Notes
Amoebiasis
- A protozoal disease caused by Entamoeba histolytica
- High incidence in tropical countries (Mexico, South America, Southeast Asia, and Africa)
- Global incidence rate is approximately 10%
- Common in crowded urban communities
- Two types of amoeba are found:
- E. dispar and E. coli are commensal (non-pathogenic) and primarily feed on bacteria.
- E. histolytica is invasive, larger and actively moving, and contains red blood cells.
Transmission, Life Cycle, and Pathology
- Transmitted by ingestion of E. histolytica cysts, not trophozoites
- Convalescent and asymptomatic carriers are significant sources of infection, as patients with acute dysentery only pass trophozoites (non-infectious).
- Excystation occurs in the lower ileum and caecum.
- A cyst with 4 nuclei can divide to 8 trophozoites through binary fission
- Trophozoites invade tissue and cause tissue damage, leading to necrosis (cell death).
Clinical Manifestations
- Infection sites: Cecum, ascending colon, and sigmoid colon are commonly affected. Small intestine is rarely involved.
- Lesion types: Lesions may be patchy or continuous, starting as discrete erosions that develop into microabscesses and extending into mucosal and muscularis mucosa. This develops into typical flask-shaped ulcers.
- Blood vessels: Blood vessels can be involved, causing thrombosis or bleeding into the intestinal lumen. Portal vein involvement can lead to amoebae reaching the liver.
- Cysts: E. histolytica cysts are not found in tissues.
- Mild: Gradual onset, constipation instead of diarrhea, and presence of scant trophozoites in stool.
- Moderate: Patient unwell, passing blood-stained mucus (mucus and blood) with stools 5-15 times/day (walking dysentery). Patient may appear non-toxic.
- Severe: Toxic-appearing patient; severe diarrhea (more than 15 motions/day); dehydrated, tenesmus and numerous trophozoites and leukocytes in stool. This can lead to toxic megacolon with severe bowel ulceration and dilation.
- Chronic amoebic dysentery: Characterized by vague bouts of abdominal pain with cecum and colon full of gas. This condition includes periodic diarrhea and constipation, similar to IBS.
- Amoeboma: Asymptomatic or tender abdominal mass that can be confused with cancer.
Complications
- Peritonitis
- Bleeding
- Intestinal obstruction
- Intestinal intussusception
- Stricture of colon
- Brain or liver abscess
Diagnosis
- Definitive diagnosis involves demonstration of E. histolytica trophozoites during acute infection and cysts in remission.
- Amoebic fluorescent antibody tests are positive in approximately 96% of invasive amoebiasis cases and 100% in cases with liver abscess.
Treatment
-
Metronidazole (Flagyl): Effective against tissue ameobiasis (but not cysts).
- 200 mg after oral or intravenous administration.
- Dose: 800 mg three times daily or 5 days.
-
Tinidazole: Single-dose 2 g or sustained-release regimen.
- Can be used in oral infections.
- Amoebic liver abscess requires aspiration to determine presence of trophozoites (which are 80% sensitive).
- Metronidazole 800 mg TDS for 10 days and chloroquine in addition to metronidazole.
- Tinidazole 2g for 3 days and chloroquine according to protocol.
Amoeba Liver Abscess
- Originates from infection of liver by E. histolytica trophozoites that circulate from the colon via the portal system, leading to cell necrosis (destruction), creating thick chocolate-brown pus.
- Only trophozoites are typically visible in the pus and walls of the abscess; cysts are not.
- 50% of patients with abscesses report a prior history of dysentery.
- Single abscess is usual, but multiple abscesses may also be observed; often seen after 5 months.
Giardiasis
- Worldwide occurrence in areas with inadequate hygiene and sanitation.
- Humans are the main reservoir.
- Infection occurs via contaminated drinking water or food (direct fecal-oral spread).
- Cysts survive for weeks outside the human body.
Giardia's Life Cycle
- Characterized by ingestion of cysts
- Cysts excyst in the small intestine, releasing trophozoites.
- Trophozoites multiply in the gut.
- Some trophozoites encyst and are passed in feces.
Other Key Points
- Metronidazole acts on amoeba, Giardia, Trichomonas, other anaerobic microbes, and has partial effects on Leishmania.
- Metronidazole is excreted unchanged via urine and inhibits liver enzymes.
- 70% excreted unchanged in urine.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Related Documents
Description
Test your knowledge on the treatment and management of amoebiasis and giardiasis in this quiz. Explore various aspects including medications, symptoms, and methods of infection related to these illnesses. Perfect for medical students or health professionals looking to refresh their understanding.
