intestinal` protozoa. giardia lamblia giardia trophozoites ( sem) giardia trophozoites (light...
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Giadriasis: Clinical Picture
Asymptomatic infections ( majority)
Symptomatic Infections:
Typical picture: IP 1-2 wks followed by diarrhoea for about 6 wks,
Atypical : Severe diarrhoea , malabsorption especially in children
Giardiasis: Laboratory diagnosis
• Stools examination :cysts or trophozoits
• Examination of duodenal contents : trophozoites
ENTAMOEBA HISTOLYTICA…
500 million people are infected. 100,000 deaths per year. Worldwide distribution. It is a waterborne infection.
There are 6 species of Entamoeba:
histolytica dispar
hartmanni coli
gingivalis polecki
Entamoeba histolytica : amoebae that are pathogenic.
E. dispar The non invasive form .
The 2 amoebae can’t be distinguish by microscopic
observation.
E. histolytica vs E. dispar
Mode of infection
Water, food
Flies can act as vector..
Can be sexually transmitted person -to -person contacts
Not a zoonosis
Entamoeba histolytica
Life cycle
Trophozoite: vegetative stage, must encyst to survive in the environment. It is a fragile structure. Pre cyst: encysting trophozoites disgorging any undigested food.
Cyst: infective stage. Resist to the harsh conditions of the environment.
Entamoeba histolytica
The infective dose can be as little as 1 cyst. be as little as 1 cyst.
The incubation period can be from few days to can be from few days to few weeks depending on the infective dose
Cysts can survive for weeks at appropriate weeks at appropriate temperature and humidity.
Entamoeba histolytica
PATHOLOGY
Intsetinal amoebiasis :
Remarkable and unique ability a to hydrolyse host host
tissues with their active cysteine proteases present on the surface membrane of the trophozoite.
Lesions are found in the caecum, appendix, or colon.
They may heal. If perforation of the colon occurs, They may heal. If perforation of the colon occurs,
My lead to a peritonitis that can lead to death. Amoeboma
Granuloma obstructing the bowel
Entamoeba histolytica
E. Histolytica in mucosa. in mucosa.
Numerous Numerous
trophozoites can be
seen with ingested seen with ingested erythrocytes.
PATHOLOGY
Intsetinal amoebiasis :