Difference between revisions of "Giardia"
Jump to navigation
Jump to search
m |
|||
Line 10: | Line 10: | ||
}} | }} | ||
<br> | <br> | ||
+ | ==Recognition== | ||
[[Image:Giardia cysts.jpg|thumb|right|150px|''Giardia'' cysts from gerbil faecea - H.D.A. Lindquist, U.S. EPA]] | [[Image:Giardia cysts.jpg|thumb|right|150px|''Giardia'' cysts from gerbil faecea - H.D.A. Lindquist, U.S. EPA]] | ||
[[Image:Giardia lamblia life cycle.jpg|thumb|right|150px|''Giardia lamblia'' life cycle - Wikimedia Commons]] | [[Image:Giardia lamblia life cycle.jpg|thumb|right|150px|''Giardia lamblia'' life cycle - Wikimedia Commons]] | ||
[[Image:Giardia lamblia.jpg|thumb|right|150px|''Giardia lamblia'' - Janice Carr]] | [[Image:Giardia lamblia.jpg|thumb|right|150px|''Giardia lamblia'' - Janice Carr]] | ||
[[Image:Giardia.jpg|thumb|right|150px|''Giardia'' - Joaquim Castellà Veterinary Parasitology Universitat Autònoma de Barcelona]] | [[Image:Giardia.jpg|thumb|right|150px|''Giardia'' - Joaquim Castellà Veterinary Parasitology Universitat Autònoma de Barcelona]] | ||
+ | *Flagellate protozoa | ||
+ | |||
+ | *Found in the intestine of humans | ||
+ | |||
+ | *Associated with chronic [[Intestine Diarrhoea - Pathology|diarrhoea]] | ||
+ | |||
+ | *Foundin both wild and domestic animals | ||
+ | |||
+ | *15-20μm long | ||
+ | |||
+ | *Pear-shaped | ||
+ | |||
+ | *8 flagella | ||
+ | |||
+ | *Large adhesive discs to hold onto intestinal mucosa | ||
+ | |||
+ | ==Life Cycle== | ||
+ | |||
+ | *Simple and direct | ||
+ | |||
+ | *Trophozoites attach to intestinal wall | ||
+ | |||
+ | *Reproduce by binary fission | ||
+ | |||
+ | *Form cysts of 10μm | ||
+ | **Cysts formed '''intermittently''' | ||
+ | **Immediately infective when passed in faeces | ||
+ | |||
+ | *Prepatent period of 5-6 days | ||
+ | |||
+ | ==Pathogenesis== | ||
+ | |||
+ | *Commonest cause of protozoal [[Intestine Diarrhoea - Pathology|diarrhoea]] of man in the UK | ||
+ | |||
+ | *Common in domesticated animals | ||
+ | |||
+ | *Infections often asymptomatic in domestic animals | ||
+ | **Can cause cillous 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-bourne) | ||
+ | |||
+ | *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 | ||
+ | |||
+ | ==Diagnosis== | ||
+ | |||
+ | *Faecal examination | ||
+ | **Cysts need to be distinguished from pollen grains and yeasts | ||
+ | |||
+ | *Cysts excretion is intermittent | ||
+ | **Faeces need to be collected over a 3 day period | ||
+ | |||
+ | *Cysts are '''heavy''' | ||
+ | **Needs higher density floatation fluids | ||
+ | **Do not float well in saturated sodium chloride solution | ||
+ | |||
+ | *Immunoassays | ||
+ | **Detecting cyst antigen in faeces | ||
+ | |||
+ | ==Control and Treatment== | ||
+ | |||
+ | *Sanitation and hygiene | ||
+ | **Minimise risk of human infection | ||
+ | |||
+ | *Boil (or sterilise through other means) drinking water in regions of the world where drinking water may be contmainated | ||
+ | |||
+ | *Avoid uncooked foodstuffs | ||
+ | **Contaminated by washing | ||
+ | |||
+ | *Treatments | ||
+ | **Metronidazole | ||
+ | ***Flagyl, Torgyl | ||
+ | **Fenbendazole | ||
+ | ***Panacur | ||
+ | |||
+ | *[[Vaccines - WikiBlood|Vaccination]] | ||
+ | **Killed trophozoites | ||
+ | **Availbale in the USA for cats and dogs | ||
+ | **Decreases the excretion and viability of cysts | ||
+ | **Decreases environmental pressure |
Revision as of 18:39, 23 November 2008
This article is still under construction. |
|
Recognition
- Flagellate protozoa
- Found in the intestine of humans
- Associated with chronic diarrhoea
- Foundin both wild and domestic animals
- 15-20μm long
- Pear-shaped
- 8 flagella
- Large adhesive discs to hold onto intestinal mucosa
Life Cycle
- Simple and direct
- Trophozoites attach to intestinal wall
- Reproduce by binary fission
- Form cysts of 10μm
- 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 cillous 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-bourne)
- 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
- G. duodenalis most commonly infects humans
Diagnosis
- Faecal examination
- Cysts need to be distinguished from pollen grains and yeasts
- Cysts excretion is intermittent
- Faeces need to be collected over a 3 day period
- Cysts are heavy
- Needs higher density floatation fluids
- Do not float well in saturated sodium chloride solution
- Immunoassays
- Detecting cyst antigen in faeces
Control and Treatment
- Sanitation and hygiene
- Minimise risk of human infection
- Boil (or sterilise through other means) drinking water in regions of the world where drinking water may be contmainated
- Avoid uncooked foodstuffs
- Contaminated by washing
- Treatments
- Metronidazole
- Flagyl, Torgyl
- Fenbendazole
- Panacur
- Metronidazole
- Vaccination
- Killed trophozoites
- Availbale in the USA for cats and dogs
- Decreases the excretion and viability of cysts
- Decreases environmental pressure