Protoza ( Entamoeba Histolytica )

Question 1

Classification of protozoa

Answer 1

Free living : naeglaria fawleri- acathomeba

Pathogenic : entamoeba histolytica
Non pathogenic :
Entamoeba coli
Entamoeba ginivalis ( buccal cavity )
Entamoeba hartmani
Entamoeba dispar
Lodamoeba butshli
Endolimax nana

Question 2

Life cycle

Answer 2

(6)
1-entamoeba live in large intestine
2- man ingests contaminated food with cysts or external auto infection ( diagnostic = infective )
3- after ingesting , pass from stomach to ileum and begin to excyst ( ph change)
4- nuclei (4) go under binary division to 8 to give 8 trophozoite
5- in sub mucosal colon , cecam they multiply ( colonization that needs bacteria )
6- some of them precyst then cyst and some are pathogenic

Question 3

Patho

Answer 3

4
4
4

1- the colonization needs presence of bacteria ( asymptomatic)
2- then it break barriers entering enterocytes to make flask shaped ulcer with healthy surronding
3- more extension : peritonitis, coloic perforation , appendicitis
4- erosion in blood vessels in wall causing haemorrhage and amobeic empoli especially in patients taking corticosteroids, stress , chronic diseases eg cancer and malnutrition

1- asymptomatic stage
-90 % are
-They are carriers
-Present danger as they can transmit the cyst eg food handlers

2- intestinal amboesis
Amoebic colitis : distension - diahrrea- constipation

Amoebic desentry
- dark stool +blood + mucus
- foul smelling
- with tensmus

Fulmanint colitis
- ulceration
- necrosis
- patient is fibrile / toxic

Amoeboma / granuloma
Misdiagnosed cliniclly as cancer

Extraintestinal amoebisas
1- liver
- hepatitis
• Enlargement of liver
• This involvement is due to repeated invasions eithier by active colic infection or toxins ( so i can see a liver specmen without tropozoite )
- ALA (6)
• 5:10% in adult males
• in upper right lobe
• pathology : center of it has chocolate pus ( anchovay sauce pus ) and this is liqufied necrotic liver tisse , bacteriollgically sterile and has no amoeba , in the perihary there is normal tissue invaded by amoeba ( عشان كده اخد العينة من الجوانب)
• symptoms: fever - cough - right hypochondrial pain
• signs : hepatomegaly- jaundice
• complication : rupture and spread to diaphram to lung , pericardium , peritonal cavity or to skin and aaw forming fistula

2- pleuropulmonary (2)
- the commenst complication of ala
- in form of pnemnautis , lung abcess, bronchohepatic fustula

3- cutaneus amoebiaisis(2)
- extension around anus
- sinus from amiebic abscess

4- cerebral amoebiasis (2)
-secondary amoebic meningeencephalitis
-Onset progresses rapidly to death without therapy

Question 4

Diagnosis

Answer 4

6
1- history
2- clinical
3- laboratory
- detection of cyst in well formed stool
Or detection of trophozoites engulfing RBCS in fresh desentry
- sigmoidoscopy : biopsy from the edge of ulcer ( seeing trophozoite , flask shaped ulcer)
- copro antigen : detecting specific antigens in stool
- serology ( ELISA ) in invasive amoebiasis ( لو فيه desentry )
- PCR
- ALA
• liver aspirate
-in large abscess in a mean for treatment ( - tenderness)
-Trophozoites are in margins
• imaging of liver by CT, MRI or X RAYS

Question 5

Treatment

Answer 5

Amoebicidal ~> luminal ( colitis)
~> tissue ( abscess )

•Asymptomatic: deloxanide furate ( luminal )
•Intestinal colitis : deloxanide furate + tissue amoebecidal if there is abcess ( tinidazole wtih good compliance ) ( metronedazole with bad complinace )

• ALA :
Deloxanide furate
Tisse amoebacidal
Hosptilization
Needle aspiration