Difference between revisions of "Candidiasis"

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=Introduction=
 
=Introduction=
Candidiasis is a fungal infection caused by [[Candida spp.|''Candida'' spp.]], [[File:C albicans germ tubes.jpg|200px|right|thumb|''Candida'' spp]] most commonly ''Candida ablicans'' that affects many species.
+
Candidiasis is a '''fungal infection''' caused by [[Candida spp.|''Candida'' spp.]], [[File:C albicans germ tubes.jpg|200px|right|thumb|''Candida'' spp]] most commonly '''''Candida ablicans''''' that affects many species.
The yeast is normally present on skin and in [[Alimentary System Overview - Anatomy & Physiology|GI tract]] and symptoms of disease are usually only seen in immunocompromised animals following opportunistic infection.  It is most common in the bird but has also been reported in horses, pigs, cows, sheep, cats and dogs - in particular neonates.  
+
The yeast is normally present on '''skin''' and in the [[Alimentary System Overview - Anatomy & Physiology|GI tract]]. Symptoms of disease are usually only seen in '''immunocompromised''' animals following '''opportunistic''' infection.  It is most common in the bird but has also been reported in [[Candidiasis – Rabbit|rabbits]], horses, pigs, cows, sheep, cats and dogs - in particular neonates.  
  
 
==Clinical signs==  
 
==Clinical signs==  
Lesions are found on mucous membranes and at mucocutaneous junctions most commonly. The disease will usually remain localised to the mucocutaneous junctions, but on rare occasions it may spread systemically.
+
Lesions are found on '''mucous membranes''' and at '''mucocutaneous junctions''' most commonly. The disease will usually remain '''localised''' to the mucocutaneous junctions, but on rare occasions it may spread '''systemically'''.
  
 
Gross clinical signs include:
 
Gross clinical signs include:
* Exudative, papular, pustular to ulcerative dermatitis
+
* '''Exudative''', '''papular''', '''pustular''' to '''ulcerative dermatitis'''
* Raised, circular, white plaques or ulcers with overlying scabs
+
* '''Raised''', '''circular white plaques''' or '''ulcers''' with overlying '''scabs'''
* Keratinous thickening of tissue
+
* '''Keratinous thickening''' of tissue
* Stomatitis and otitis externa
+
* [[Stomatitis|'''Stomatitis''']] and [[Otitis Externa - Cat and Dog|'''otitis externa''']]
  
 
Microscopically there is evidence of:
 
Microscopically there is evidence of:
*Spongiotic neutrophilic pustular inflammation
+
*Spongiotic neutrophilic pustular [[Inflammation|'''inflammation''']]
*Parakeratosis
+
*'''Parakeratosis'''
*Ulcerations
+
*'''Ulcerations'''
*Superficial exudate containing organisms
+
*Superficial [[Exudate|'''exudate''']] containing organisms
  
Infection may cause a also cause a variety of other clinical signs depending on the species and the site of infection, for example mastitis, arthritis, diarrhoea and general malaise.
+
Infection may cause a also cause a variety of '''other clinical signs''' depending on the '''species''' and the '''site of infection''', for example [[Mastitis|mastitis]], [[Arthritis|arthritis]], [[Diarrhoea|diarrhoea]] and general malaise.
  
 
==Predisposing factors==
 
==Predisposing factors==
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* Indwelling urinary or intravenous catheters
 
* Indwelling urinary or intravenous catheters
 
* Antibiotic administration
 
* Antibiotic administration
* Corticosteroid administration
 
  
 
==Diagnosis==
 
==Diagnosis==
Diagnosis can be confirmed via microscopic examination and identification of the fungus following a skin scrap of the lesion. The fungus should be visible after staining with a Gram, Methylene Blue or Wrights stain. It is a gram positive ovoid, budding yeast with or without hyphae. Culture of a sample in Sabourauds Dextrose agar or Blood agar should also confirm diagnosis.
+
Diagnosis can be confirmed via '''microscopic examination''' and '''identification of the fungus''' following a '''skin scrape''' of the lesion. The fungus should be visible after staining with a Gram, Methylene Blue or Wrights stain. It is a '''gram-positive ovoid''', '''budding yeast''' with or without '''hyphae'''. '''Culture''' of a sample in Sabourauds Dextrose agar or Blood agar should also confirm diagnosis.
  
 
==Treatment==
 
==Treatment==
Topical anti-fungals are used to treat the infection.  
+
'''Topical''' or '''systemic anti-fungals''' are used to treat the infection.  
  
 +
==Prognosis==
 +
Prognosis depends on both the severity of infection and the animal affected.
  
=Candidasis in birds=
 
  
 +
=Candidasis in birds=
 +
[[Image:Sour Crop.jpg|thumb|right|200px|Sour Crop - Copyright Professor Andrew N. Rycroft, BSc, PHD, C. Biol.F.I.Biol., FRCPath]]
 
==Signalment==
 
==Signalment==
Candidiasis ''aka'' thrush/sour crop/crop mycosis is common in '''neonatal psittacine birds'''. It occurs primarily as a result of '''immunosuppression''' and '''trauma''' to the ingluvies. Hypothermia, feeding too cold or too hot formula which results in crop-burn, poor nutrition, longterm antibiotic therapy, hypovitaminosis A and systemic illness from other causes are all predisposing causes.  
+
Candidiasis ''aka'' '''thrush/sour crop/crop mycosis''' is common in '''neonatal psittacine birds'''. It occurs primarily as a result of '''immunosuppression''' and '''trauma''' to the ingluvies. Hypothermia, feeding too cold or too hot formula which results in crop-burn, poor nutrition, longterm antibiotic therapy, hypovitaminosis A and systemic illness from other causes are all predisposing causes.  
  
 
==Clinical Sings==
 
==Clinical Sings==
The bird may present with '''inflammation''' and '''delayed emptying''' of the '''ingluvies'''.
+
The bird may present with '''inflammation''' and '''delayed emptying''' of the '''ingluvies'''. On examination of the crop surrounding structures, there are normally grey-white lesions and a whitish necrotic material present. There may also be thickening of the crop wall.  
  
 
==Diagnosis==
 
==Diagnosis==
Line 47: Line 49:
 
==Treatment==
 
==Treatment==
 
An '''antifungal drug''' is indicated for the treatment of candidiasis. The presence of hyphae is suggestive of invasion of the mucosa by the yeast and the potential for a systemic infection. Therefore, a '''systemic antifungal''' such as oral itraconazole (for 7 days) is recommended  along with a topical antifungal such as nystatin BID or TID for 7–10 days.
 
An '''antifungal drug''' is indicated for the treatment of candidiasis. The presence of hyphae is suggestive of invasion of the mucosa by the yeast and the potential for a systemic infection. Therefore, a '''systemic antifungal''' such as oral itraconazole (for 7 days) is recommended  along with a topical antifungal such as nystatin BID or TID for 7–10 days.
.
+
 
 
==Prognosis==
 
==Prognosis==
 
The presence of hyphae on cytological examination suggests a severe infection and potential systemic spread, and therefore a '''poor''' prognosis. Without evidence of hyphae the prognosis is improved.
 
The presence of hyphae on cytological examination suggests a severe infection and potential systemic spread, and therefore a '''poor''' prognosis. Without evidence of hyphae the prognosis is improved.
  
==References==
+
=References=
 
Forbes NA & Altman RB (1998) '''Self-Assessment Colour Review Avian Medicine''' ''Manson Publishing Ltd''
 
Forbes NA & Altman RB (1998) '''Self-Assessment Colour Review Avian Medicine''' ''Manson Publishing Ltd''
  
 
Girling, S (2004) '''Diseases of the digestive tract of psittacine birds''' ''In Practice 2004 26: 146-15''
 
Girling, S (2004) '''Diseases of the digestive tract of psittacine birds''' ''In Practice 2004 26: 146-15''
  
 +
Merck & Co (2009) '''The Merck Veterinary Manual''' (Ninth Edition), ''Merial''
  
 +
{{Learning|flashcards = [[Avian Medicine Q&A 16]]}}
  
 
[[Category:Cutaneous Mycoses]]
 
[[Category:Cutaneous Mycoses]]
 
[[Category:To Do - Fungi]]
 
[[Category:To Do - Fungi]]
 
[[Category: To Do - Siobhan Brade]]
 
[[Category: To Do - Siobhan Brade]]
 +
[[Category:To Do - Manson review]]

Revision as of 20:58, 2 August 2011

Introduction

Candidiasis is a fungal infection caused by Candida spp.,

Candida spp

most commonly Candida ablicans that affects many species.

The yeast is normally present on skin and in the GI tract. Symptoms of disease are usually only seen in immunocompromised animals following opportunistic infection. It is most common in the bird but has also been reported in rabbits, horses, pigs, cows, sheep, cats and dogs - in particular neonates.

Clinical signs

Lesions are found on mucous membranes and at mucocutaneous junctions most commonly. The disease will usually remain localised to the mucocutaneous junctions, but on rare occasions it may spread systemically.

Gross clinical signs include:

  • Exudative, papular, pustular to ulcerative dermatitis
  • Raised, circular white plaques or ulcers with overlying scabs
  • Keratinous thickening of tissue
  • Stomatitis and otitis externa

Microscopically there is evidence of:

  • Spongiotic neutrophilic pustular inflammation
  • Parakeratosis
  • Ulcerations
  • Superficial exudate containing organisms

Infection may cause a also cause a variety of other clinical signs depending on the species and the site of infection, for example mastitis, arthritis, diarrhoea and general malaise.

Predisposing factors

  • Immunosuppressive drugs
  • Immunosuppressive disease
  • Indwelling urinary or intravenous catheters
  • Antibiotic administration

Diagnosis

Diagnosis can be confirmed via microscopic examination and identification of the fungus following a skin scrape of the lesion. The fungus should be visible after staining with a Gram, Methylene Blue or Wrights stain. It is a gram-positive ovoid, budding yeast with or without hyphae. Culture of a sample in Sabourauds Dextrose agar or Blood agar should also confirm diagnosis.

Treatment

Topical or systemic anti-fungals are used to treat the infection.

Prognosis

Prognosis depends on both the severity of infection and the animal affected.


Candidasis in birds

Sour Crop - Copyright Professor Andrew N. Rycroft, BSc, PHD, C. Biol.F.I.Biol., FRCPath

Signalment

Candidiasis aka thrush/sour crop/crop mycosis is common in neonatal psittacine birds. It occurs primarily as a result of immunosuppression and trauma to the ingluvies. Hypothermia, feeding too cold or too hot formula which results in crop-burn, poor nutrition, longterm antibiotic therapy, hypovitaminosis A and systemic illness from other causes are all predisposing causes.

Clinical Sings

The bird may present with inflammation and delayed emptying of the ingluvies. On examination of the crop surrounding structures, there are normally grey-white lesions and a whitish necrotic material present. There may also be thickening of the crop wall.

Diagnosis

Diagnosis is based on identification of oval yeasts and hyphae on cytological smears taken from swabs and crop washes or aspirates. Wrights stain can be used to demonstrate the yeasts. There should be no evidence of an inflammatory response. The presence of hyphae indicates that the crop may have been penetrated and the infection has spread systemically.

Treatment

An antifungal drug is indicated for the treatment of candidiasis. The presence of hyphae is suggestive of invasion of the mucosa by the yeast and the potential for a systemic infection. Therefore, a systemic antifungal such as oral itraconazole (for 7 days) is recommended along with a topical antifungal such as nystatin BID or TID for 7–10 days.

Prognosis

The presence of hyphae on cytological examination suggests a severe infection and potential systemic spread, and therefore a poor prognosis. Without evidence of hyphae the prognosis is improved.

References

Forbes NA & Altman RB (1998) Self-Assessment Colour Review Avian Medicine Manson Publishing Ltd

Girling, S (2004) Diseases of the digestive tract of psittacine birds In Practice 2004 26: 146-15

Merck & Co (2009) The Merck Veterinary Manual (Ninth Edition), Merial


Candidiasis Learning Resources
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Flashcards
Test your knowledge using flashcard type questions
Avian Medicine Q&A 16