Candidiasis Flashcards
(29 cards)
What are fungi?
Eukaryotic organisms with cell wall containing chitin and/or cellulose
May be:
Sexual or asexual
Uni- or multi-cellular
Yeasts or moulds
Estimated to be at least 250,000 species
What are the clinically important fungi?
Yeasts Candida species C. albicans C. glabrata C. tropicalis C. krusei C. parapsilosis Others
Cryptococcus spp.
C. neoformans
C. gattii
Moulds Dimorphic fungi -Blastomyces dermatitidis -Coccidioides immitis -Histoplasma capsulatum Aspergillus species Zygomycetes Dermatophytes Pneumocystis carinii Many others
What is the normal flora of the candida species? and what can altered host defense do? What type of immunity is important for containment?
Worldwide distribution
Normal flora
Mouth, lower GI in 10-50%
Altered host defense can result in infection and invasion
Cell mediated immunity important for containment
What is candidiasis?
Superficial infection
- Mucosal
- Oropharyngeal (thrush)
- Esophageal- Vulvovaginal
- Oropharyngeal (thrush)
- Skin
- Localized
- Chronic Mucocutaneous candidiasis (where the immune system isn’t suppressing it at all)
Deep infection
- Localized:
- Intra-abdominal, urinary
Candidemia (blood stream infection) with dissemination
- Endocarditis, lung, CNS, renal, bone/joint, hepatosplenic, ocular, etc
What are the risk factors for oropharyngeal candidiasis?
Risk factors
Diabetes, corticosteroids, antibiotics, immunodeiciency (esp. HIV), dentures
What are the manifestation of oropharyngeal candidiasis?
Manifestations
Raised white patches or redness alone
What is the dianostic confirmations of oropharyngeal candidiasis?
Clinical: bleeding base after scraping
Yeast, pseudohyphae on microscopy
What is the management for oropharyngeal candidiasis?
Alter predisposing conditions
Topical or systemic antifungals
What are the risk factors for esophageal candidiasis?
Immunodeficiency
HIV, organ transplant, chemotherapy
What are the manifestations for esophageal candidiasis?
Retrosternal chest pain with swallowing
What is the diagnostic criteria for esophageal candidiasis?
Visualization +/- biopsy with endoscopy
What is the management for esophageal candidiasis?
Alter predisposing conditions
Systemic antifungals x 14-21 days
What are the manifestations for cutaneous candidiasis?
Immunocompetent:
- Infections in skin folds, nails & paronychium
Chronic Mucocutaneous Candidiasis (CMC)
- Skin, mucous membranes, hair, nails
Due to immune defect, usually diagnosed in infants or childhood
What is the diagnostic criteria for cutaneous candidiasis?
Skin scrapings for fungal stain and culture
What is the management for cutaneous candidiasis?
Topical or systemic (CMC) antifungal drugs
What are the risk factors for candidemia and disseminated candidiasis?
Immunosuppression
- Neutropenia, Corticosteroids
Broad-spectrum antibacterial antibiotics
Central IV catheters (risk increases with lumen #)
Abdominal surgery
Total parenteral nutrition (TPN)
Severe burns
Colonization (especially candiduria)
Acute renal failureWhat is one main risk factor to develop candidemia and disseminated candidiasis?
having a central line!!! you are more than 8 times more likely to develop this infection
How is candidiasis diagnosed?
Microscopy = budding yeast
Gram +, calcofluor white fluorescence
Culture:
Regular solid media, blood culture bottles
Identification:
Germ tube + : presumptive C. albicans
Commercial strips (API): 48-72 h
MALDI-TOF / mass spectrometry: minutes!
What is the germ tube test?
From pure culture:
Suspend in serum
Incubate 35-37oC
Examine after 2-3 h
Positive test = C. albicans
Early projection without constriction at junction with parent cell
What are considerations to use when using antifungals for candidemia/
Expected infecting species
- Susceptibility can often be predicted
“Margin for error”
- Broader spectrum for unstable patients
Safety
- Potential for nephrotoxicity with AmB products
Cost
Is it okay to wait a while before you get treatment?
no, the apache II scale showed that if a person doesn’t get good therapy early their chances for mortality ar e greatly increased.
What does the role of non-albicans species show?
There’ve been more and more non-albicans coming up and less and less albicans.
What are echinocandins and why are they good?
Echinocandins are newer drugs that are active against most fluconazole resistant strains but are more safe than those fluconazole ones.
Attractive features:
Activity -vs- potentially fluconazole resistant Candida strains
C. krusei, C. glabrata, C. lusitaniae
Tolerability
Not nephrotoxic
Comparable to FLU, superior to AMPHO
What did they use to use to treat candida spp. usually?
fluconazole. when there was no previous treatment with fluconazole and they were hemodynamically stable.
