Candidiasis Flashcards
What are the virulence factors of candidiasis?
GIT commensals - hospitalised patient’s skin and mucosa
Opportunistic - immunosuppression
Biofilm formers (lines, devices)
What is the 4th cause of BSI in hospitalised patients?
Candidiasis, 50% of which are ICU patients
What is the definition of invasive candidiasis?
Isolation of candida from a sterile site
1. Candidemia
2. Deep seated
What is the number 1 cause of systemic fungal infections?
Candida
What is the in hospital mortality of invasive candidiasis?
50%
Outcomes are worse if treatment is delayed
What are the intra-abdominal types of invasive candidiasis?
- Peritonitis
- Abscess (post-surgery)
- Cholecystitis
- Choleangitis
What does the diagnosis of invasive candidiasis require?
Isolation from sterile site
AND
Clinical evidence
If diagnosing an invasive candidiasis, what is the maximum length of time of the drain from which the fluid is taken allowed to be?
<24h
Can you use swabs to diagnose invasive candidiasis?
No
What are disease related breaches in barrier defence?
Burns
Mucositis
GI perforation
Pancreatitis
Anastomotic leak
What are intervention related breeches in barrier defence?
IV lines
TPN
GI surgery
Urological intervention
How can candida colonise the body?
Antibiotic use
Environmental acquisition
To which organs does candidemia often disseminate to haematongeously?
Endocarditis
Endopthalmitis
Renal
Brain
Hepatosplenic
Which host factor co-morbidities increase the risk of candida infection?
Cancer (haem>solid organ)
Diabetes
Transplant (BM>solid organ)
Liver failure
Renal failure
Which host factor drugs increase the risk of candida infection?
Corticosteroids
Chemotherapy
Anti-rejection
Biologics
Which host factor genes increase the risk of candida infection?
SNPs at loci
- CD58
- LCE4A-C1orf68
- TAGAP
What is the gold standard of candida diagnosis?
Culture
What is the sensitivity and specificity of BDG?
60-80%
What is the NPV and PPV of BDG?
NPV - high (use to exclude)
PPV - low (anti-fungal overuse)
Which circumstances can cause a false positive BDG
Hemodialysis
Immunoglobulin infusion
Albumin
Surgical gauze
What improves the performance of BDG?
Serial samples
Cut off >250
What is the benefit of BDG combined with other biomarkers?
Inconclusive benefit
What is the Candida Colonisation Index?
Ratio of the number of non-blood sites colonised with candida spp/total number of sites
What are adjuncts to diagnosis invasive candidiasis?
- Candida Colonisation Index
- Candida Score
- Ostrosky-Zeichner Clinical Prediction Rule
What is the Candida Score?
TPN (1)
Surgery (1)
Severe sepsis (2)
Multifocal candida colonisation (1)
>2.5 is positive
What is the Ostrosky-Zeichner Clinical Prediction Rule?
Mechanical ventilation >48h AND systemic ABs AND CVP PLUS 1 of any
- major surgery
- pancreatitis
- immunosuppressive agents
- TPN
- dialysis
Which strategy is used when patient has risk factors for candidiasis?
Prophylactic strategy
Which strategy is used when patient has clinical features of fungal sepsis?
Empiric strategy
Which strategy is used when patient has fungal biomarkers?
Pre-emptive strategy
Which strategy is used when patient has positive fungal culture, PCR or histology?
Targeted strategy
Which sites do echinocandins not penetrate?
CNS
Urine
What is the preferred initial therapy for all candida species?
Echinocandins
Which candida species can fluconazole be considered as an alternative therapy?
C. albicans
C. tropicalis
C. parapsilosis
Which candida species can amphotericin B be considered as an alternative therapy?
C. glabrata
C. krusei
C. auris
What is the preferred agent for candida krusei?
Voriconazole
Which drugs interact with triazoles?
CYP450 inhibitors
Which anti-fungal treatments need TDM?
Voriconazole
Flucytosine
What is the target site of terbinafine?
Squalene -> squalene epoxide
What is the target site of azoles?
Lanosterol -> ergosterol
What is the target site of amphotericin B?
Cell membrane
What is the target site of nystatin?
Cell membrane
What is the target site of echinocandins?
Beta-glucan synthase
What is the target site of flucytosine?
Fungal RNA
How do you monitor for candidiasis resolution?
Clearance cultures
Clinical
Radiological
What are poor prognostic factors for invasive candidiasis?
GI source
Lack of source control
Short BC TTP
Delayed treatment
Lack of ID consult
Severe sepsis
Severe comorbidities
Which candida species are intrinsically resistance to the azaleas?
C. kruseii
C. guillermondi
C. glabrata
Which candida species has acquired resistance to echinocandins?
C. glabrata
What are the most common mechanisms of acquired resistance?
Target alteration (aspergillus)
Drug efflux regulation (glabrata)
Which gene mutation is seen in azole resistant aspergillus?
ERG11
What are the drivers of anti fungal resistance?
Widespread human use
Agricultural crop spraying
Which gene mutation is seen in echinocandin resistance?
FKS 1/2
What is the most common cause of candidemia in SA?
C. parapsilosis
How many candida species are on the WHO fungal priority pathogens list?
4/11
1. C.auris
2. C. albicans
3. C. parapsilosis
4. C. tropicalis
