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| − | ==Histoplasmosis==
| + | [[Histoplasmosis]] |
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| − | |<gallery>Image:Histoplasmosis canine spleen.jpg|<center><p>'''Histoplasmosis in a canine spleen'''</p><sup>Copyright Professor Andrew N. Rycroft, BSc, PHD, C. Biol.F.I.Biol., FRCPath</sup></center></gallery>
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| − | *''Histoplasma capsulatum''
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| − | *Non-contageous, systemic mycosis
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| − | *Commonly pulmonary infections occur
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| − | **Other organs can be involved
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| − | **Involves the reticuloendothelial system
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| − | **Intestinal form can also occur
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| − | *Acute and chronic disease can occur
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| − | *Endemic to the USA
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| − | **Isolated cases have been reported in Europe
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| − | *Respiratory infection
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| − | **Infection via ingestion can also occur
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| − | *Affects dogs, cats, cattle, horses and humans
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| − | *Found in soil contaminated by bird droppings, decaying vegetation and in caves inhabited by bats
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| − | |<gallery>Image:Histoplasmosis lung.jpg|<center><p>'''Histoplasmosis lesions in lungs'''</p><sup>Copyright Professor Andrew N. Rycroft, BSc, PHD, C. Biol.F.I.Biol., FRCPath</sup></center></gallery>
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| − | *Fine, branching, septate hyphae with smooth-walled pyriform to spherical microconidia and large, thick-walled tuberculate macroconidia on simple conidiophores
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| − | *Dimorphic fungi
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| − | *Hard to demonstrate in smears as the organisms is very small
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| − | **Stain with Giemsa or Wright and examine under oil immersion lens
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| − | *Present intracellularly in [[Macrophages - WikiBlood|macrophages]] as oval yeast cells with few buds
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| − | **Clear halo is seen around the darker staining central material
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| − | *Grows on Sabouraud's Dextrose agar
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| − | **Creamy white colonies, turning tan coloured and then brown
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| − | *Also grows on Blood agar
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| − | **Small, white yeast-like colonies
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| − | *Test using immunodiffusion, complement fixation and counterimmunoelectrophoresis
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| − | **Skin test of little value as it only indicates exposure
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| − | *Treatment with [[Antifungal Drugs#Polyene Antifungals|Amphotericin B]]
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| − | **If [[Antifungal Drugs#Polyene Antifungals|Amphotericin B]] is contra-indicated, [[Antifungal Drugs#Imidazoles|imidazoles]] can be given orally
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| − | *The prognosis is poor in acute and disseminated cases
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| − | {| align="center"
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| − | |<gallery>Image:Histoplasmosis canine spleen silver stain.jpg|<center><p>'''Histoplasmosis in a canine spleen using silver stain'''</p><sup>Copyright Professor Andrew N. Rycroft, BSc, PHD, C. Biol.F.I.Biol., FRCPath</sup></center>
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| − | Image:Histoplasmosis phagocyte.jpg|<center><p>'''Histoplasmosis phagocyte'''</p><sup>Copyright Professor Andrew N. Rycroft, BSc, PHD, C. Biol.F.I.Biol., FRCPath</sup></center>
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| − | Image:Histoplasmosis tuberculate chlamydospores.jpg|<center><p>'''Histoplasmosis tuberculate chlamydospores'''</p><sup>Copyright Professor Andrew N. Rycroft, BSc, PHD, C. Biol.F.I.Biol., FRCPath</sup></center></gallery>
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| − | |}
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| | ==Zygomycosis== | | ==Zygomycosis== |