5. Historical BackgroundHistorical Background
Giardia intestinalis was first observed by AntonyGiardia intestinalis was first observed by Antony
van Leeuwenhoek (1681) – A Dutch tradesmanvan Leeuwenhoek (1681) – A Dutch tradesman
in his own stool - and he described them asin his own stool - and he described them as
animalculesanimalcules
He is also called the “father of Microbiology”He is also called the “father of Microbiology”
In 1859 a physician named Vilem LamblIn 1859 a physician named Vilem Lambl
observed G. intestinalis in stool of children withobserved G. intestinalis in stool of children with
diarrhoeadiarrhoea
7. Giardia lambliaGiardia lamblia
Is a flagellated protozoan parasite that colonizes andIs a flagellated protozoan parasite that colonizes and
reproduces in the small intestines causing Giardiasis.reproduces in the small intestines causing Giardiasis.
The Giardia parasite attaches to the epithelium by aThe Giardia parasite attaches to the epithelium by a
ventral adhesive disc.ventral adhesive disc.
Reproduces via Binary fission.Reproduces via Binary fission.
Does not spread via bloodstream nor does it spread toDoes not spread via bloodstream nor does it spread to
other parts of the Gastrintestinal tract, but remainsother parts of the Gastrintestinal tract, but remains
confined to the lumen of the small intestines.confined to the lumen of the small intestines.
10. Giardia lambliaGiardia lamblia
Trophozoites absorb their nutrient from theTrophozoites absorb their nutrient from the
lumen of the small intestines and are anaerobes.lumen of the small intestines and are anaerobes.
If the organism is split and stained, it has a veryIf the organism is split and stained, it has a very
characteristic pattern that resembles a familiarcharacteristic pattern that resembles a familiar
“Smiley face”symbol“Smiley face”symbol
12. CystsCysts
Are not killed by chlorinationAre not killed by chlorination
Killed or removed by Boiling, Iodine treatmentKilled or removed by Boiling, Iodine treatment
or Filtrationor Filtration
One cyst gives rise to two trophoizoites (oneOne cyst gives rise to two trophoizoites (one
amebic cyst produces eight trophoites).amebic cyst produces eight trophoites).
13. Giardia lamblaGiardia lambla
Affects humans but is also one of the mostAffects humans but is also one of the most
common parasites infecting Cats, Dogs andcommon parasites infecting Cats, Dogs and
birds.birds.
The mammalian hosts include:The mammalian hosts include:
CowsCows
Beavers (also called Beaver fever)Beavers (also called Beaver fever)
Deer &Deer &
SheepSheep
14. Life CycleLife Cycle
Ingestion of dormant cysts in contaminatedIngestion of dormant cysts in contaminated
water, food or by the faecal – oral routewater, food or by the faecal – oral route
(through poor hygiene practices)(through poor hygiene practices)
Cyst Trophozoite CystCyst Trophozoite Cyst
15. Lab DiagnosisLab Diagnosis
Trophozoites or Cysts in diarrhoeal stoolTrophozoites or Cysts in diarrhoeal stool
In formed stool only Cysts are seenIn formed stool only Cysts are seen
Antigen Detection in stool by ELISAAntigen Detection in stool by ELISA
String TestString Test
No Serlogical Test availableNo Serlogical Test available
18. Trichomas VaginalisTrichomas Vaginalis
A protozoan parasite that exists only in theA protozoan parasite that exists only in the
Trophozoite form i.e. there is NO cyst formTrophozoite form i.e. there is NO cyst form
Pear ShapedPear Shaped
Motile and the motility is called Jerky. WobblingMotile and the motility is called Jerky. Wobbling
or Rotating motionor Rotating motion
21. Trichomonas vaginalis:Trichomonas vaginalis:
trophozoites are oval introphozoites are oval in
shape, 10-23 µm in length,shape, 10-23 µm in length,
with four anterior flagellawith four anterior flagella
of equal length and a fifthof equal length and a fifth
flagellumflagellum
on the margin of the shorton the margin of the short
undulating membrane.undulating membrane.
22. Trichomonas vaginalis:Trichomonas vaginalis: thethe
infection is usuallyinfection is usually
acquiredacquired
by venereal contacts.by venereal contacts.
The male is the mostThe male is the most
important transmitter ofimportant transmitter of
the infection.the infection.
Trichomonas vaginalisTrichomonas vaginalis::
T.vaginalisT.vaginalis is responsibleis responsible
forfor vaginitis and urethralvaginitis and urethral
discharge.discharge.
Symptomatic infection isSymptomatic infection is
more common in womenmore common in women
during the reproductiveduring the reproductive
period.period.
23. TRICHOMONASTRICHOMONAS VAGINALISVAGINALIS
DiagnosisDiagnosis is usuallyis usually
obtained byobtained by
microscopicmicroscopic
examination of urine,examination of urine,
vaginal or urethralvaginal or urethral
discharge or swabs ofdischarge or swabs of
prostatic secretions.prostatic secretions.
CultureCulture is possible onis possible on
different media:different media:
cysteine-peptone-liver-cysteine-peptone-liver-
maltosemaltose
and trypticase-yeastand trypticase-yeast
extract-maltose media.extract-maltose media.