Difference between revisions of "Giardia"

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{{unfinished}}
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{{Taxobox
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|name              =Giardia
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|kingdom            =Protista
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|sub-kingdom        =Biciliata
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|phylum            =Metamonada
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|super-class        =Eopharyngea
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|class              =Trepomonadea
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|sub-class          =Diplozoa
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|super-order        =
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|order              =Giardiida
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|sub-order          =
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|super-family      =
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|family            =Diplomonadidae
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|sub-family        =
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|genus              =Giardia
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|species            =
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}}
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[[Image:Giardia lamblia life cycle.jpg|thumb|right|150px|''Giardia lamblia life cycle'' - Wikimedia Commons]]
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[[Image:Giardia lamblia.jpg|thumb|right|150px|''Giardia lamblia'' - Janice Carr]]
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[[Image:Giardia.jpg|thumb|right|150px|''Giardia'' - Joaquim Castellà Veterinary Parasitology Universitat Autònoma de Barcelona]]
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[[Image:Giardia cyst.jpg|thumb|right|150px|''Giardia'' cyst - Courtesy of the Laboratory of Parasitology, University of Pennsylvania School of Veterinary Medicine]]
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==Overview==
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These protozoan parasite are found in humans as well as wild and domestic animals. They are a common cause of severe [[Diarrhoea|diarrhoea]] as part of the clinical symptoms [[Giardiasis|giardiasis]].
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==Recognition==
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''Giardia spp.'' are flagellate protozoa with 8 flagella, 6 of which emerge from the body and are used in motility. They are 15-20μm long, pear shaped with a flat ventral surface. The most unique feature of this protozoa is the presence of a large adhesive disk in the flat surface that is used for attaching to the intestinal mucosa.
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==Life Cycle==
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*Simple and direct
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*Trophozoites attach to intestinal wall
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*Reproduce by binary fission
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*Form cysts of 10μm
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**Multi-nucleate cysts formed '''intermittently'''
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**Immediately infective when passed in faeces
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*Prepatent period of 5-6 days
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==Pathogenesis==
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*Commonest cause of protozoal [[Diarrhoea|diarrhoea]] of man in the UK
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*Common in domesticated animals
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*Infections often asymptomatic in domestic animals
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**Can cause villous atrophy leading to malabsorption
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**Infection can persist for weeks to months if not treated
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==Epidemiology==
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*Infection via direct oral-faecal route or through contaminated water source (water-borne)
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*Wild animals may act as a source of infection for humans
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**E.g. Beavers
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*Divided into 7 species
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**''G. duodenalis'' most commonly infects humans
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***Some subspecies are zoonotic
  
{{toplink
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{{Learning
|backcolour =
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|flashcards = [[Giardia_Flashcards|Giardia Flashcards]]
|linkpage =Parasites
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|Vetstream = [https://www.vetstream.com/canis/search?s=protozoa Protozoa]
|linktext =PARASITES
 
|pagetype=Bugs
 
|sublink1=Protozoa
 
|subtext1=PROTOZOA
 
 
}}
 
}}
<br>
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[[Image:Giardia cysts.jpg|thumb|right|150px|''Giardia'' cysts from gerbil faecea - H.D.A. Lindquist, U.S. EPA]]
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{{unfinished}}
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[[Category:Miscellaneous_Protozoa]]
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[[Category:To_Do_-_Parasites]]

Latest revision as of 17:57, 4 June 2016

Giardia
Kingdom Protista
Sub-kingdom Biciliata
Phylum Metamonada
Super-class Eopharyngea
Class Trepomonadea
Sub-class Diplozoa
Order Giardiida
Family Diplomonadidae
Genus Giardia
Giardia lamblia life cycle - Wikimedia Commons
Giardia lamblia - Janice Carr
Giardia - Joaquim Castellà Veterinary Parasitology Universitat Autònoma de Barcelona
Giardia cyst - Courtesy of the Laboratory of Parasitology, University of Pennsylvania School of Veterinary Medicine

Overview

These protozoan parasite are found in humans as well as wild and domestic animals. They are a common cause of severe diarrhoea as part of the clinical symptoms giardiasis.

Recognition

Giardia spp. are flagellate protozoa with 8 flagella, 6 of which emerge from the body and are used in motility. They are 15-20μm long, pear shaped with a flat ventral surface. The most unique feature of this protozoa is the presence of a large adhesive disk in the flat surface that is used for attaching to the intestinal mucosa.

Life Cycle

  • Simple and direct
  • Trophozoites attach to intestinal wall
  • Reproduce by binary fission
  • Form cysts of 10μm
    • Multi-nucleate cysts formed intermittently
    • Immediately infective when passed in faeces
  • Prepatent period of 5-6 days

Pathogenesis

  • Commonest cause of protozoal diarrhoea of man in the UK
  • Common in domesticated animals
  • Infections often asymptomatic in domestic animals
    • Can cause villous atrophy leading to malabsorption
    • Infection can persist for weeks to months if not treated

Epidemiology

  • Infection via direct oral-faecal route or through contaminated water source (water-borne)
  • Wild animals may act as a source of infection for humans
    • E.g. Beavers
  • Divided into 7 species
    • G. duodenalis most commonly infects humans
      • Some subspecies are zoonotic


Giardia Learning Resources
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Vetstream
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Canis, Felis, Lapis or Equis
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Flashcards
Test your knowledge using flashcard type questions
Giardia Flashcards