giardia presen...notes

8/13/2019 Giardia Presen...Notes

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PROTOZOA FLAGELLATESThese are Protozoa using flagella for locomotion and

food procurement.

1. Taxonomical classification

Subphylum - Sarcomastigophora

Superclass- Mastigophora- Moving by flagella

ClassZoomastigophoraLacking chromatophores

nutrient holozoic, reproduction asexual.

2. Divided into two groups:

A. Those living in digestive tract and genitalia,transmission from person to person without

biological vector. I.e. Giardia lamblia, Chilomastix

mesnili, Trichomonas Spp of genitalia and GI tract


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B. Haemoflagellates- Parasites ofblood stream and tissue,requiring blood suckingarthropods as biological vectors

Family Trypanosomatidae

1. Genus Leishmania- Spp forhuman Leishmaniasis

2. Genus Trypanosoma -Spp-forhumans Trypanosomiasis

Leishmania

Trypanosoma
http://en.wikipedia.org/wiki/Image:Trypanosoma_sp._PHIL_613_lores.jpghttp://en.wikipedia.org/wiki/Image:Trypanosoma_sp._PHIL_613_lores.jpg


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GIARDIA LAMBLIA


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Giard ia lamb l ia(Intestinalis)

Causes Human giardiasis Phylum (Protozoa)

Class: ZOOMASTIGOPHOREA

Order: Diplomonadidae

Family Hexamitidae--- (Two nuclei lying side

by side)

Genus GIARDIA

Species Giardia lamb lia (In testin al is)


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Morphology & Life cycle of Giardia

lamblia1

Giard ia lambl ia

It colonises and reproduces in the smallintestine, causing Giardiasis.

Giardia lamblia has both cyst and trophozoiteforms.

Cyst has four nuclei and it is the Infectivestages of man

Trophozoite is the vegetative and reproductiveand pathogenic stage . It has 8 flagella andtwo nuclei

Both cysts and trophozoites can be found inlose stool


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Major characteristics

Distinguishing features of the trophozoites

Two nuclei

Large karyosome and no peripheralchromatin, giving the two nuclei a haloappearance.

Cysts are distinguished by a retracted

cytoplasm. The protozoan lacks mitochondria,
http://en.wikipedia.org/wiki/Mitochondriahttp://en.wikipedia.org/wiki/Mitochondria


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Causes Human giardiasis

Under a normal compound

light microscope, Giardiaoften looks like a "clownface," with two nucleioutlined by adhesive

discs above dark regionthat forms the "mouth."

Cysts are oval, have fournuclei, and have clearly

visible axonemes(exostyle).

Giardia lambliahas nomitochondria

Giardia trophozoite

Note the 2 anterior nuclei (eyes),the ventral adhesive disc, the

axostyle and the 8 flagella.
http://en.wikipedia.org/wiki/Microscopehttp://en.wikipedia.org/wiki/Axostylehttp://en.wikipedia.org/wiki/Mitochondriahttp://en.wikipedia.org/wiki/Mitochondriahttp://en.wikipedia.org/wiki/Axostylehttp://en.wikipedia.org/wiki/Microscope


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Life cycle


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Life cycle


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Life cycle of Giardia lamblia2

Transmission: Infection is acquired byingestion of mature cyst- the resistantforms found in the environment

Excystation: Cysts undergo excystation insmall intestine to releases trophozoites

Cysts pass through the stomach,exposed to gastric acid/low pH andemerge in the lower stomach or upper

small intestine as a trophozoite. Each cyst has four nuclei and produces

2 trophozoites


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Trophozoites multiply by longitudinalbinary fission, remaining in the lumen ofthe proximal small bowel where theycan be free or attached to the mucosa

by a ventral sucking diskEncystation:

Trophozoites migrating to the distal

small intestine undergo a process ofencystation as moisture in faecesdwindles , and pH becomes acidic withincreased effect of bile salts


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Encystation: Encystation requires the synthesis of the cell wall

that will resist the hash environment outside

In encystation trophozoite retract the flagella intoaxonemes and assume the appearance of 4 pairsof curve bristles

Cytoplasm becomes thin and a tough hyaline

membrane is secreted to form the cyst wall.Cysts:

They have rigid cell walls and are non-dividing,can survive several months in cold water. Cysts

can resist desiccation in the environment


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Life cycle


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Epidemiology:Giardia infection can occur

through ingestion of dormant cysts in

contaminated water, food, or by the fecal-oral

route (through poor hygiene practices).

Cyst can survive for weeks to months in cold

water, found in contaminated wells and water

systems, and even clean-looking streams. May occur in city reservoirs and persist after water

treatment,

Giardia cysts are resistant to conventional water

treatment methods such as chlorination

Boiling water is recommended


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Transmission

Faecal-oral transmission may occur, in daycare centres due to poor hygiene

practices.

Children workers, family members of

infected individuals are at risk of infections

Not all Giardia infections are symptomatic,

many people serve as carriers of the

parasite.


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Transmission2

Risks of infection are increased by reservoir hosts-

Giardia is the Most common parasites infectingcats, dogs Cows, sheep, deer (in recreationalareasZoonotictransmission:

Person-to-person transmission: Possible whencysts are passed in the stool or shortly afterward

Pathogenesis, symptom s and sign s

Characteristic location is of the trophozoites is theglandular crypts of duodenal-jejunal mucosa.

Do not invade the tissue but feed on mucosa secretions,may damage villi
http://en.wikipedia.org/wiki/Zoonotichttp://en.wikipedia.org/wiki/Zoonotic


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Pathogenesis2:

Incubation period 5-20 days

Large surface of mucosa covered by trophozoitesinterfering with fat absorption hence steatorrheic typeof stool with excess secretion mucus and fat.

Malabsorption may cause vitamin B12 deficiency in

chronic infection People with recurring Giardia infections, particularlythose with a lack of IgA, may develop chronicdisease.

Lactase deficiencymay develop Gallbladder may be parasitized causing blockage of

bile duct- may result in jaundice

Duodenal irritation dehydration and dull epigastric

pain may occur
http://en.wikipedia.org/wiki/Lactose_intolerancehttp://en.wikipedia.org/wiki/Lactose_intolerancehttp://en.wikipedia.org/wiki/Lactose_intolerancehttp://en.wikipedia.org/wiki/Lactose_intolerance


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Symptoms2

It usually causes "explosive diarrhoea" and whileunpleasant, is not fatal. In healthy individuals,the condition is usually self-limiting, although theinfection can be prolonged in patients who areimmunocompromised, or who have decreasedgastric acid secretion.


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Symptomsof infection include (in order of frequency)

diarrhoea, malaise, excessive gas. (often flatulence

or a foul or sulphuric-tasting belch, known to be sonauseating in taste that it can cause the infected

person to vomit),

Clinical manifestations- It is a clinical disease of

mainly infants and children Clinical Disease is Self limiting in 4-7 weeks

There is Intermittent shedding of cysts

Acute diarrhoea- 5 -7days, abdominal cramps &

bloating, Anorexia & feverdiminished interest in

food, possible vomiting and weight loss.

Pus and blood are not commonly present in the stool.

Di i


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Diagnosis

Diagnosis of Giardiasis is done by observation

of cysts and/or trophozoites in faeces orduodenal aspirates under a microscope

Multiple microscope stool examinations are

recommended, since the cysts and trophozoitesare not shed consistently.

Accurate diagnosis may require an antigen test

especially in none endemic areas


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Giardia lamblia trophozoites &

cysts

cysts
http://www.cdfound.to.it/hTML/gia5b.htmhttp://www.cdfound.to.it/hTML/gia5.htmhttp://www.cdfound.to.it/hTML/giaLeo.htm


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Treatment: Human infection is conventionally treated

with metronidazole, tinidazole ornitazoxanide.

Given the difficult nature of testing to findthe infection, including many false

negatives, some patients should betreated on the basis of empirical evidence;


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Prevention Chlorine treatment of drinking water for Giardia

is not very successful in killing the organism.

Reliable prevention of outdoor water typicallyinvolves filtration with a filter that has a nominal1-micrometer pore size.

Most chemical treatment methods, includingcommon point-of-use treatments such as iodineand chlorine dioxide, are considered unreliablein inactivating Giardia cysts.

Water parameters such as temperature,turbidity, and dissolved solids may also affectthe effectiveness of such treatments.


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Cyst of G. lamblia

THANK YOU

& HAVE A GIARDIA FREE DAY

Chilomastix mesnili


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Other flagellates

Chilomastix mesnili


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Chilomastix mesnili

Chi lomast ix mesni l i-is a harmless commensal

flagellate whose presence in a stool specimensuggest hand to mouth faecal contamination

It has well defined trophozoite and cystic stages

Trophozoitestage has a spiral grooveextending through the middle half of the bodygiving it a pear shape

The size is about 620 microns in length and 310 microns in breath.

It has a nucleus measuring 34 micronsmedially situated near the pole with distinctcentral karyosome


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CILIATES

CILIATES B l tidi li


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CILIATES- Balantidium coli The ciliates belong to the family Ciliophora.

They possess simple cilia or compound ciliaryorganelles

This are extensions of ectoplasmic membranesand are used for locomotion and attachments.

They have 2 types of nuclei and a largecontractile vacuole.

They have cystostome which they use as cellmouth and Cytopyge as anal pore

Balantidium coli is the only representativeprotozoa in man

Balantidium Spp have been reported as naturalparasites in hogs, monkies, cockroaches etc.


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Balant id ium co l i

Balantidium coli is the only member of the ciliate

family to cause human disease

It is the largest protozoa that parasitize human

The organism is widely distributed in warmerclimates where human infections most commonly

occur.

It inhabit the large intestine, caecum and terminalileum where they feed on bacteria

There are both cyst and trophozoite stages


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Balantidium coli

Classification

Phylum Protozoa

Class Ciliata The disease is known as balantidiosis, or

balantidial dysentery Transmitted by fecal-

oral route


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Morphology:

Trophozoites

Trophozoites of B. colimeasures 50-150m in length

and 40-70 mm in width but have been known toattain lengths of up to 200m

They are oval in shape and covered in short cilia.

The cilia are present in young cysts and may be

seen slowly rotating, But after prolonged encystment, the cilia disappear.

A funnel shaped cytosome (cell mouth) can be seennear the anterior end and a cytophage at the other

end. The cytoplasm contains numerous food vacuolesand one or two contractile vacuoles.

Nuclei: It has two nuclei- One large bean shapedmacronucleus, micronucleus in the centre of thecurvature of macronucleus.


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Life cycle


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Life cycle

Reproduction byTraverse binary

fission

Cytoplasm divideinto two daughter

cells

Nuclei do notmultiply when

encysted


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Clinical Disease

Severe B. coliinfections may resemble

amoebiasis. Symptoms include diarrhoea,

nausea, vomiting and anorexia. The diarrhoeamay persist for long periods of time resulting in

acute fluid loss. B. coli also has the potential to

penetrate the mucosa resulting in

ulceration. Extra-intestinal disease has alsobeen reported butrarely.

L b t Di i


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Laboratory Diagnosis Wet preparations of fresh and

concentrated stool preparations

reveal the characteristic cystsand trophozoites.

They are easier to identify inwet preparations thanpermanently stained faecalsmears.

In unstained preparation, theorganisms are easilyrecognized because of their

size and rapid revolvingrotation.

In a stained preparation, thecharacteristic macro and

micronuclei may be observed


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Balat id ium col i -Commensal

Note macronuclei

A) A cyst of B. coli, the only ciliateparasite of humans, in an

unstained wet mount offormalin-preserved faeces. Thelarge macronucleus is visible asa clear area at the right side ofthe cyst.

B) A trichrome-stained trophozoiteof B. coli. The cytostome isseen at the top of the organismand the macronucleus is thedark-staining structure locatedin midbody. Cilia are visible onthe surface as hair-like

projections.May cause diarrhoea/dysentery

AB

Note macronuclei


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THANK YOU


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GIARDIASIS

Manifestation of infection Colonization of the gut results in

inflammation and villous atrophy,

Reduced the gut's absorptive capability. In humans, infection is symptomatic only

about 50% of the time,.


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SymptomsIt usually causes "explosivediarrhea" and while unpleasant, is not fatal. In

healthy individuals, the condition is usually self-limiting, although the infection can be prolongedin patients who are immunocompromized, orwho have decreased gastric acid secretion.

People with recurring Giardia infections,particularly those with a lack of IgA, may developchronic disease.

Lactase deficiencymay develop in an infection

with Giardia, however this usually does notpersist for more than a few weeks before a fullrecovery


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Symptoms

Symptoms of infection include (in order offrequency) diarrhea, malaise, excessive gas(often flatulence or a foul or sulphuric-tastingbelch, which has been known to be so

nauseating in taste that it can cause the infectedperson to vomit),

steatorrhoea(pale, foul smelling, greasy stools),epigastric pain, bloating, nausea, diminishedinterest in food, possible (but rare) vomiting

which is often violent, weight loss. Pus and blood are not commonly present in

the stool.
http://en.wikipedia.org/wiki/Steatorrhoeahttp://en.wikipedia.org/wiki/Steatorrhoea


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Giardiasis cause of Vitamin B12

deficiency, due to intestinal malabsorption

of fats.
http://en.wikipedia.org/wiki/Vitamin_B12_deficiencyhttp://en.wikipedia.org/wiki/Vitamin_B12_deficiencyhttp://en.wikipedia.org/wiki/Vitamin_B12_deficiencyhttp://en.wikipedia.org/wiki/Vitamin_B12_deficiency


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Diagnosis

Tratment:

Given the difficult nature of testing to find the infection, includingmany false negatives, some patients should be treated on the basisof empirical evidence; (treating based on symptoms).

Human infection is conventionally treated with metronidazole,tinidazoleor nitazoxanide. Although Metronidazole is the currentfirst-line therapy, it is mutagenicin bacteria and carcinogenicinmice, so should be avoided during pregnancy.[3]

One of the most common alternative treatments is (found in Oregongrape root, goldenseal, yellowroot, and various other plants).[citationneeded] Berberinehas been shown to have an antimicrobialand anantipyreticeffect.[citation needed] Berberine compounds causeuterinestimulation, and so should be avoided in pregnancy.[citationneeded] High doses of berberine can cause bradycardiaandhypotension. [11]
http://en.wikipedia.org/wiki/Empirical_evidencehttp://en.wikipedia.org/wiki/Metronidazolehttp://en.wikipedia.org/wiki/Tinidazolehttp://en.wikipedia.org/wiki/Nitazoxanidehttp://en.wikipedia.org/wiki/Mutagenichttp://en.wikipedia.org/wiki/Carcinogenichttp://en.wikipedia.org/wiki/Oregon_grape_roothttp://en.wikipedia.org/wiki/Oregon_grape_roothttp://en.wikipedia.org/wiki/Goldensealhttp://en.wikipedia.org/wiki/Yellowroothttp://en.wikipedia.org/wiki/Wikipedia:Citation_neededhttp://en.wikipedia.org/wiki/Wikipedia:Citation_neededhttp://en.wikipedia.org/wiki/Berberinehttp://en.wikipedia.org/wiki/Antimicrobialhttp://en.wikipedia.org/wiki/Antipyretichttp://en.wikipedia.org/wiki/Wikipedia:Citation_neededhttp://en.wikipedia.org/wiki/Uterinehttp://en.wikipedia.org/wiki/Wikipedia:Citation_neededhttp://en.wikipedia.org/wiki/Wikipedia:Citation_neededhttp://en.wikipedia.org/wiki/Bradycardiahttp://en.wikipedia.org/wiki/Hypotensionhttp://en.wikipedia.org/wiki/Hypotensionhttp://en.wikipedia.org/wiki/Bradycardiahttp://en.wikipedia.org/wiki/Wikipedia:Citation_neededhttp://en.wikipedia.org/wiki/Wikipedia:Citation_neededhttp://en.wikipedia.org/wiki/Uterinehttp://en.wikipedia.org/wiki/Wikipedia:Citation_neededhttp://en.wikipedia.org/wiki/Antipyretichttp://en.wikipedia.org/wiki/Antimicrobialhttp://en.wikipedia.org/wiki/Berberinehttp://en.wikipedia.org/wiki/Wikipedia:Citation_neededhttp://en.wikipedia.org/wiki/Wikipedia:Citation_neededhttp://en.wikipedia.org/wiki/Yellowroothttp://en.wikipedia.org/wiki/Goldensealhttp://en.wikipedia.org/wiki/Oregon_grape_roothttp://en.wikipedia.org/wiki/Oregon_grape_roothttp://en.wikipedia.org/wiki/Carcinogenichttp://en.wikipedia.org/wiki/Mutagenichttp://en.wikipedia.org/wiki/Nitazoxanidehttp://en.wikipedia.org/wiki/Tinidazolehttp://en.wikipedia.org/wiki/Metronidazolehttp://en.wikipedia.org/wiki/Empirical_evidence


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Dientamoeba fragilis

Trophozoites of Dientamoeba fragilishas

two nuclei..

The karyosomes within the nuclei are

variable in appearance; often they are

fragmented into 3 to 8 pieces but in other

instances they may appear as a single

mass. There is no peripheral chromatin on


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Dientamoeba fragilis-Trophozoites


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Other flagellates

Chilomastix mesnili

Chil ti ili


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Chilomastix mesnili

Chilomastix mesnili-is a harmless commensal flagellate

whose presence in a stool specimen suggest hand tomouth faecal contamination hence possibility of amoeba

infection.

It has well defined trophozoite and cystic stages

Trophozoitestage has a spiral groove extendingthrough the middle half of the body giving it a pear shape

The size is about 620 microns in length and 310

microns in breath.

It has a nucleus measuring 34 microns mediallysituated near the pole with distinct central karyosome


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Cyst of Chilomastix mesnili

Cysts are pear-lemon shaped, colourless

measuring 7 -10 microns in length x46

microns in breadth

Chilomatix mesnili is a normal inhabitant of

coecum where the trophosites live on

enteric bacteria in the lumen of glands andmultiply by binaly fission


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CILIATES


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CILIATES

The ciliates belong to the family Ciliophora.

They possess simple cilia or compound ciliaryorganelles

This are extensions of ectoplasmic membranes

and are used for locomotion and attachments.

They have 2 types of nuclei and a large

contractile vacuole.

They have cystostome which they use as cell

mouth and Cytopyge as anal pore Balantidium Spp have been reported as natural

parasites in hogs, monkies, cockroaches etc.


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Balant id ium co l i

Balantidium coli is the only member of the ciliate

family to cause human disease

It is the largest protozoa that parasitize human

The organism is widely distributed in warmerclimates where human infections most commonly

occur.

The organisms inhabit the large intestine, caecum

and terminal ileum where they feed on bacteria

There are both cyst and trophozoite stages


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Balantidium coli

Classification

Phylum Protozoa

Class Ciliata

It is the only ciliated protozoa infectious

infectious for humans

The disease is known as balantidiosis,balantidiosis, or balantidial dysentery

Transmitted by fecal-oral route

Morphology:


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Morphology: The cyst is spherical or ellipsoid and

measures from 50 - 70m. It contains 1 macro (large bean shaped)and 1

micronucleus (within macronucleus).

The cilia are present in young cysts and maybe seen slowly rotating,

But after prolonged encystment, the cilia

disappear.

Morphology


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Morphology

Trophozoites

Trophozoites of B. colimeasures 50-100m in length and 40-70

mm in width but have been known to attain lengths of up to 200m

They are oval in shape and covered in short cilia.

A funnel shaped cytosome (cell mouth) can be seen near theanterior end and a cytophage at the other end.

The cytoplasm contains numerous food vacuoles and one ortwo contractile vacuoles.

It contains 1 macronucleus (large bean shaped) and 1 micronucleus (in thecentre of the curvature of macronucleus).

In an unstained preparation, the organisms are easily recognizedbecause of their size and rapid revolving rotation.

In a stained preparation, the characteristic macro andmicronuclei may be observed.


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Life cycle


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Life cycle


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Laboratory Diagnosis


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Laboratory Diagnosis

Wet preparations of fresh and concentrated

stool preparations reveal the characteristic

cysts and trophozoites.

They are easier to identify in wetpreparations than permanently stained faecal

smears.


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THANK YOU


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Symptoms2

It usually causes "explosive diarrhea" and whileunpleasant, is not fatal. In healthy individuals,the condition is usually self-limiting, although theinfection can be prolonged in patients who are

immunocompromised, or who have decreasedgastric acid secretion.[3]

People with recurring Giardia infections,particularly those with a lack of IgA, may develop

chronic disease. Lactase deficiencymay develop in an infection

with Giardia infection,


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Diagnosis

Giardia lamblia infection in humans is frequently misdiagnosed. Accurate diagnosis requires an antigen test or, if that is unavailable, an ova and

parasite examination of stool.

Multiple stool examinations are recommended, since the cysts and trophozoites arenot shed consistently.

Tratment:

Given the difficult nature of testing to find the infection, including many falsenegatives, some patients should be treated on the basis of empirical evidence;(treating based on symptoms).

Human infection is conventionally treated with metronidazole, tinidazoleornitazoxanide. Although Metronidazole is the current first-line therapy, it is mutagenicin bacteria and carcinogenicin mice, so should be avoided during pregnancy.[3]

One of the most common alternative treatments is (found in Oregon grape root,goldenseal, yellowroot, and various other plants).[citation needed] Berberinehasbeen shown to have an antimicrobialand an antipyreticeffect.[citation needed]Berberine compounds cause uterinestimulation, and so should be avoided inpregnancy.[citation needed] High doses of berberine can cause bradycardiaandhypotension. [11]

Giardia lamblia trophozoites & cysts
http://en.wikipedia.org/wiki/Empirical_evidencehttp://en.wikipedia.org/wiki/Metronidazolehttp://en.wikipedia.org/wiki/Tinidazolehttp://en.wikipedia.org/wiki/Nitazoxanidehttp://en.wikipedia.org/wiki/Mutagenichttp://en.wikipedia.org/wiki/Carcinogenichttp://en.wikipedia.org/wiki/Oregon_grape_roothttp://en.wikipedia.org/wiki/Goldensealhttp://en.wikipedia.org/wiki/Yellowroothttp://en.wikipedia.org/wiki/Wikipedia:Citation_neededhttp://en.wikipedia.org/wiki/Berberinehttp://en.wikipedia.org/wiki/Antimicrobialhttp://en.wikipedia.org/wiki/Antipyretichttp://en.wikipedia.org/wiki/Wikipedia:Citation_neededhttp://en.wikipedia.org/wiki/Uterinehttp://en.wikipedia.org/wiki/Wikipedia:Citation_neededhttp://en.wikipedia.org/wiki/Bradycardiahttp://en.wikipedia.org/wiki/Hypotensionhttp://en.wikipedia.org/wiki/Hypotensionhttp://en.wikipedia.org/wiki/Bradycardiahttp://en.wikipedia.org/wiki/Wikipedia:Citation_neededhttp://en.wikipedia.org/wiki/Uterinehttp://en.wikipedia.org/wiki/Wikipedia:Citation_neededhttp://en.wikipedia.org/wiki/Antipyretichttp://en.wikipedia.org/wiki/Antimicrobialhttp://en.wikipedia.org/wiki/Berberinehttp://en.wikipedia.org/wiki/Wikipedia:Citation_neededhttp://en.wikipedia.org/wiki/Yellowroothttp://en.wikipedia.org/wiki/Goldensealhttp://en.wikipedia.org/wiki/Oregon_grape_roothttp://en.wikipedia.org/wiki/Carcinogenichttp://en.wikipedia.org/wiki/Mutagenichttp://en.wikipedia.org/wiki/Nitazoxanidehttp://en.wikipedia.org/wiki/Tinidazolehttp://en.wikipedia.org/wiki/Metronidazolehttp://en.wikipedia.org/wiki/Empirical_evidence


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Giardia lamblia trophozoites & cysts
http://www.cdfound.to.it/hTML/gia5.htmhttp://www.cdfound.to.it/hTML/giaLeo.htmhttp://www.cdfound.to.it/hTML/gia5b.htm


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As well as waterborne sources, fecal-oraltransmission can also occur, for examplein day care centres, where children may

have poor hygiene practices. Those whowork with children are also at risk of beinginfected, as are family members ofinfected individuals. Not all Giardia

infections are symptomatic, and manypeople can unknowingly serve as carriersof the parasite.


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Treatment in animals

Cats can be cured easily, lambs usually simply lose weight, but in

calves the parasites can be fatal and often are not responsive toantibiotics or electrolytes.

Carriers among calves can also be asymptomatic. Dogs have a highinfection rate, as 30% of the population under one year old areknown to be infected in kennels.

The infection is more prevalent in puppies than in adult dogs. This

parasite is deadly for chinchillas, so extra care must be taken byproviding them with safe water.

Infected dogs can be isolated and treated, or the entire pack at akennel can be treated together regardless. Kennels should also bethen cleaned with bleach or other cleaning disinfectants.

The grass areas used for exercise should be considered

contaminated for at least one month after dogs show signs ofinfection, as cysts can survive in the environment for long periods oftime. Prevention can be achieved by quarantine of infected dogs forat least 20 days and careful management and maintenance of aclean water supply.


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Giard ia lamb lia(Lamblia intest inal is,


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Giard ia duodenal is) Life cycle Giardia lamb l iais a flagellatedprotozoan

It colonises and reproduces in the small intestine,causing Giardiasis.

It attaches to the epitheliumby a ventraladhesive disc,

Reproduction is by longitudinal binary fission.

Giardiasis remains confined to the lumenof the smallintestine, does not spread via the bloodstream, nor doesit spread to other parts of the gastro-intestinal tract,

Giardia trophozoitesabsorb their nutrients from thelumen of the small intestine, and are anaerobes.

If the organism is split and stained, it has a verycharacteristic pattern that resembles a smiley face.
http://en.wikipedia.org/wiki/Flagellatehttp://en.wikipedia.org/wiki/Epitheliumhttp://en.wikipedia.org/wiki/Ventralhttp://en.wikipedia.org/wiki/Binary_fissionhttp://en.wikipedia.org/wiki/Lumen_(anatomy)http://en.wikipedia.org/wiki/Gastrointestinal_tracthttp://en.wikipedia.org/wiki/Trophozoitehttp://en.wikipedia.org/wiki/Anaerobehttp://en.wikipedia.org/wiki/Anaerobehttp://en.wikipedia.org/wiki/Trophozoitehttp://en.wikipedia.org/wiki/Gastrointestinal_tracthttp://en.wikipedia.org/wiki/Gastrointestinal_tracthttp://en.wikipedia.org/wiki/Gastrointestinal_tracthttp://en.wikipedia.org/wiki/Lumen_(anatomy)http://en.wikipedia.org/wiki/Binary_fissionhttp://en.wikipedia.org/wiki/Ventralhttp://en.wikipedia.org/wiki/Epitheliumhttp://en.wikipedia.org/wiki/Flagellate


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Giardiasis- Summary

Giardia lamblia (also called G. intestinalis and G. duodenalis) This organism is unicellular and infection of the host results when

environmentally resistant cysts are ingested. Growing, motile stages of theparasite, referred to as trophozoites, emerge from the cyst (a process calledexcystation) in the proximal small intestines and colonize the intestines.

A certain number of these trophozoites travel to the more distal intestinesand will encyst, and will be passed back into the environment in the feces of

the host. The life cycle is completed when a new host ingests these cysts. This fecal-oral route of infection may result from person-to-person contact

but also often involves ingesting cysts that contaminate natural waters.Because G. lamblia infects many animals in addition to human (i.e. it hasmany reservoir hosts), mountain and forest streams are often contaminatedwith cysts that are deposited there by wildlife that inhabit these areas. It isimportant to either filter, boil or chemically treat water from these streams

before drinking it to avoid possible infection with G. lamblia.

giardia presen...notes

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