› Incidence and burden
› Most common healthcare-associated invasive fungal infection in the U.S. and Europe
› U.S. incidence: approximately 7–9 per 100,000 population
› Crude in-hospital mortality: 25–46%
› Attributable mortality: 10–20%
› Estimated 46,000 cases annually in the U.S. (pre-COVID era data)
› Species distribution (U.S. data 2017–2021)
› C. albicans: 37% (most common, generally fluconazole-susceptible)
› C. glabrata (Nakaseomyces glabrata): 30% — higher rates of fluconazole and echinocandin resistance
› C. parapsilosis: 14% — catheter-associated, echinocandin resistance emerging
› C. tropicalis: less common, associated with hematologic malignancy
› C. krusei (Pichia kudriavzevii): intrinsically fluconazole-resistant
› C. auris: 0.4% but rapidly increasing — often multidrug-resistant, nationally notifiable
› Population distribution
› 50–67% of cases occur in ICU patients
› ~37–39% in patients with malignancy
› ~10% in persons who inject drugs (PWID) — increasing proportion
› Sex distribution: slightly male predominant
› Peak incidence: elderly (> 65 years) and neonates
› Temporal trends
› COVID-19 pandemic associated with increased candidemia incidence (2020–2021)
› C. auris rapid emergence since 2016 — now endemic in multiple U.S. states
› Echinocandin resistance rising, especially in C. glabrata
› Routes of infection
› Translocation from GI tract — most common route in ICU patients
› Mucosal disruption from surgery, chemotherapy, or critical illness
› Altered microbiome from broad-spectrum antibiotics permits Candida overgrowth
› Catheter-related infection
› Biofilm formation on catheter surfaces — Candida forms robust biofilms
› Luminal (hub contamination) or extraluminal (skin flora) routes
› Hematogenous seeding from primary mucosal or skin focus
› Virulence mechanisms
› Biofilm formation — dramatically reduces antifungal susceptibility (up to 1000-fold)
› Phenotypic switching between yeast and hyphal forms
› Secretion of hydrolases (phospholipases, proteinases) — tissue invasion
› Immune evasion via mannan and beta-glucan cell wall masking
› Metastatic seeding pattern
› Hematogenous dissemination to: eyes, heart valves, kidney, liver, spleen, bone, CNS
› Biofilm on damaged endothelium or prosthetic material
› Endophthalmitis via choroidal circulation — fundus lesions represent microabscesses
› Hepatosplenic candidiasis — occurs during neutrophil recovery, immune reconstitution
› Host defense failure
› Neutropenia — impairs killing of yeast and hyphae
› Defective monocyte/macrophage function — corticosteroids, transplant immunosuppression
› Disrupted mucosal barrier — surgery, chemotherapy, CVC
Therapeutic Considerations
› Antifungal pharmacology
› Echinocandins — inhibit (1,3)-beta-D-glucan synthase; fungicidal against Candida
› Minimal drug interactions — not CYP metabolized significantly
› Poor CNS and vitreous penetration — avoid if CNS or ocular candidiasis
› Hepatic metabolism — dose adjust in severe hepatic impairment (caspofungin)
› Azoles — inhibit ergosterol synthesis (CYP51/Erg11); fungistatic against Candida
› Major CYP3A4 interactions — warfarin, calcineurin inhibitors, statins
› QTc prolongation risk — baseline and monitoring ECG
› Good CNS and vitreous penetration — preferred for CNS and ocular candidiasis
› Amphotericin B — binds ergosterol, membrane disruption; fungicidal
› Nephrotoxicity — monitor creatinine, K+, Mg2+ closely
› Infusion reactions — premedication with acetaminophen, diphenhydramine
› Resistance considerations
› Echinocandin resistance — FKS gene mutations (FKS1, FKS2); especially C. glabrata
› Fluconazole resistance — ERG11 mutations, efflux pump upregulation
› C. auris — frequently resistant to fluconazole, amphotericin B; echinocandin-resistant strains reported
› Susceptibility testing guides therapy — MIC breakpoints per CLSI or EUCAST standards
› Guideline adherence and outcomes
› ECMM Candida III study: each point decrease in EQUAL Candida Score associated with 8–9% increased 30-day mortality
› Key adherence domains: ID consultation, echinocandin first-line, CVC removal, ophthalmologic exam, echocardiography, follow-up blood cultures
› Prophylaxis — fluconazole or micafungin prophylaxis recommended in high-risk surgical or NICU populations per IDSA guidelines
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